Ben Grimm is bombarded by cosmic rays during a space trip and transforms into a super-strong rock-like creature his friends name the Thing. The crew also gained special powers and they decide to create the Fantastic Four. They face and defeat their first enemy, the Mole Man.
He and the rest of the FF are despondent on New Year's Eve due for various reasons. Before long, however, Thundra arrives in Times Square and challenges the Thing to a fight. Johnny confronts her but she fans a clock hand at great speeds and quenches his flame. The Thing accosts her but she kidnaps Alicia Masters and postpones their fight for three days. The FF return to their headquarters. Ben trains vigorously for the fight and worries over Alicia's safety. Three days later, after preparing a stadium for the fight, Thundra attacks the Thing and sends him flying out of the stadium. They continue their fight, but Thundra's rage and power gives her the upper hand. The Thing is almost defeated, but the team save him by changing him back to human form temporarily with one of Reed's machines, to which Thundra refuses to defeat a weakened Thing. Thundra releases Alicia and the team leave, with Ben humbled.
The Fantastic Four meet the Skrulls for the first time when they plan to invade Earth. The aliens take their appearances to frame them for crimes. The Thing helps the team capture the imposters and the other Skrulls fly away.
After the Fantastic Four have established their headquarters in Baxter Building in New York City, the Thing helps the team defeat the Miracle Man. Even though Johnny played a major role in their victory, Ben blames him for taking all the credit and the boy decides to leave the team.
While trying to get Johnny back in the team, the Thing experiences his first random and temporary transformation into Ben Grimm. The Fantastic Four make their first encounter with the Sub-Mariner who attacks them with a gigantic creature. The Thing destroys the monster by placing a bomb inside it and the Torch creates a vortex that hurls Namor far away into the ocean.
Doctor Doom has taken the Invisible Girl hostage to force the Fantastic Four to travel back in time on his Time Platform to retrieve Black Beard's chest which contains the Stones of Merlin. Disguising himself with a beard to hide his appearance, Ben ends up in control of a pirate ship and becomes the legendary Black Beard. After bringing back an empty chest, they escape and Doctor Doom flies away from his blazing castle.
The Thing faces Doctor Doom and the Sub-Mariner who have joined forces to destroy the Fantastic Four. When Doom pulls the Baxter Building into space, sending not only the heroes but also the Sub-Mariner to their death, the team decides to work with the Atlantean and together they defeat Doctor Doom.
The Thing faces the Puppet Master for the first time when the villain creates a puppet of him and forces him to attack Reed and Johnny. He accidentally gets exposed to a cure Reed was working on that temporarily turns him into Ben Grimm and puts an end to the Puppet Master's mind control. He meets the lovely Alicia Masters who, despite her blindness, tells him that she likes him better as the Thing. When she accidentally causes her evil step-father to fall through the window, he goes to her to try and comfort her.
Going bankrupt, the Fantastic Four accept to star in a movie to restore their financial health, unaware that it is a scheme from the Sub-Mariner to destroy them. After the boys survive the traps that he has sent them into, Namor is forced to respect his part of the deal and pay them for their participation.
Reed gives Ben his new serum to turn him back to normal and the formula seems to work. After they recall how they quickly became friends at State University and remember their military service, Ben changes again into the Thing, meaning that Reed's serum was not permanent after all.
Using their new Fantasti-Car, the Fantastic Four accompany General Ross back at his desert base to help find and stop the Hulk whom he accuses of wrecking his installations. The team confronts the Hulk for the first time and the battle takes them to a ghost town where they finally discover who is truly behind the sabotages. The Fantastic Four get their first ceremony in their honor.
Dealing with Spider-Man for the first time, the Fantastic Four take defensive measures when he breaks into their building but it turns into a battle. When he is finally given the chance, Spider-Man explains that he wants to join them but they inform him that they don't get paid so he leaves.
The Fantastic Four fly to the Blue Area of the Moon where they find remains of an ancient civilization. Then they are attacked by the Super-Apes and the Red Ghost. Both teams start to fight but they are interrupted the Watcher who teleports them to an isolated area of the moon where the Fantastic Four defeat the Red Ghost.
After a short separation to explore disappointing personal career opportunities, the Fantastic Four reunite. Realizing that the Mad Thinker and his Awesome Android have taken their headquarters, the Fantastic Four manage to neutralize the machine and outsmart the Mad Thinker by adding an unexpected human element to his equation.
Reed gives the Thing a formula that changes him back to human form, but growing tired of being a Guinea pig, Ben asks his friend to work on a cure for Alicia's blindness instead. They use Ant-Man's serum to enter a Micro-World where Doctor Doom has imposed his tyranny. Soon joined by Ant-Man, they manage to defeat their arch-enemy and free the Micro-World people. Back in their world, the Fantastic Four track down Doctor Doom who is terrorizing the city with his evil inventions and has kidnapped Alicia. They find their foe in his floating fortress but he chooses to escape by jumping off his hideout.
The team faces the Super-Skrull, a Skrull warrior that has been artificially enhanced to duplicate and outmatch all the powers of the Fantastic Four. The invader clearly has the upper hand against the four heroes until Reed devises a jammer that blocks the rays from the Skrulls' planet powering up the villain and the Human Torch is able to entrap the Super-Skrull inside a remote crater and seal it with an air-tight dome.
The Sub-Mariner captures the Fantastic Four to inform mankind that they will no longer be allowed to trespass the seven seas and the skies above. After he declares war on the surface people and invades New York with his army, the Fantastic Four use a device to evaporate the water in their enemies' helmets, forcing them to retreat back to sea.
The Thing and his teammates use Doctor Doom's time travel machine to travel to Ancient Egypt where Reed thinks they may find a cure for his beloved Alicia's blindness. They find themselves powerless and enslaved by Rama-Tut, a time traveler from the year 3000. When the team recover their senses and powers, Rama-Tut is forced to escape in his time machine and the heroes travel back to the present. Sue finds a vial with the cure they sought, but due to its radiation, it has not been transported when the heroes make it back to the present.
Heavily weakened by a virus, Reed asks his teammates to stop the Hulk who is going on a rampage in New York City. During the short struggle, both the Human Torch and the Invisible Girl fall unconscious, so it is up to the Thing to confront the green monster but he gets and is on the verge of exhaustion. Meanwhile, Reed finds a cure for his illness and the Fantastic Four regroup to fight back. Since the Hulk is battling his former teammates, the Fantastic Four decide to join forces with the Avengers, but having never fought side-by-side, they only get in each other's way. With more collaboration, they finally get rid of the Hulk who disappears into the Hudson River.
The Fantastic Four are surprised by an attack from the X-Men. But when they learn that the Mad Thinker and the Puppet Master are behind this attack, the two teams join their efforts and the villains are forced to escape.
Ben's double date at a drive-in with Alicia, Doris and his friend Johnny is interrupted by the attack of an armored villain calling himself the Beetle. With the help of the Thing, the Human Torch captures the thief and they hand him over to the police.
When they entered university, the arrogant and reclusive Victor von Doom refused to befriend Reed Richards, so Richards ended up sharing his dormitory with high school football star Benjamin Grimm, much to their delight.
Lady Dorma enlists the help of the Fantastic Four to defeat Attuma who threatens to overthrow Namor and might eventually attack the surface world. The team destroys the invader's arsenal, and while the Prince battles Attuma in a hand-to-hand combat, they covertly disable the villain's traps to even the odds.
The Thing is taken with the Fantastic Four to Planet X where they save Kurrgo's people who are doomed by the imminent collision of an asteroid with their world.
The Thing offers his help when Johnny is challenged by the Destroyer.
Doctor Doom tries to defeat the Fantastic Four by switching bodies with Mr. Fantastic and submitting them to a reducing machine but he gets caught under the ray and shrinks to nothingness.
Reed and Ben advise Sue not to interfere when she tries to dissuade her brother from tackling the Wizard alone.
The Fantastic Four have to deal with the Impossible Man whose ability to turn his body into anything he wants jeopardizes the safety of the planet.
Reed, Ben and Sue help the Human Torch after he has left the Fantastic Four to team up with the Acrobat who uses him in his criminal activities.
The Thing witnesses as Mr. Fantastic reminds Johnny the trouble they causes when he joined the Acrobat the previous month.
Back on Earth, the Fantastic Four are acclaimed by the public for being the first people to return from the Moon. When the Invisible Girl is kidnapped by Namor, Alicia convinces Ben to take her with them on their rescue operation. With her help, the team finds that Sub-Mariner was acting under the Puppet Master's control.
Reed, Sue and Ben offer their help to Johnny when he is publicly accused of being a spy, but the boy prefers to deal with the problem alone.
Reed, Sue and Ben advise Johnny to ignore the Asbestos Man's provocative letter.
The Fantastic Four learn that Doctor Doom has captured Spider-Man to force them to surrender. When they arrive to rescue the young hero, Doom has fled and they realize that the hero they rescued was an impostor.
The Fantastic Four are relieved to hear that the Human Torch is safely recovering after being critically injured while he heroically prevented a bomb from destroying a veteran's hospital.
Retelling of Spider-Man's first visit at the Fantastic Four headquarters.
Warned by the Watcher, the Fantastic Four capture the Molecule Man, a man who can control molecules and poses a threat to the whole universe.
The Hate-Monger uses a Hate Ray to encourage violence among the citizens and turns the Fantastic Four against one another. Despite their internal feud, they manage to put an end to his plans with the help of Nick Fury.
Ben Grim finds the Human Torch in a compromising situation with Alicia that provokes the Thing's anger and degenerates into a fight. When he realizes that the Puppet Master was really responsible, Alicia must intervene to convince him that her father can no longer harm them.
The Human Torch has to intervene when Doris is having a party at her house and Spider-Man decides to crash it. The rest of the Fantastic Four join the skirmish until Invisible Girl puts an end to it.
The Fantastic Four are tricked into buying a small island to conduct larger scale experiments. They realize the whole thing is a set up when they are captured by the Mole Man. During their escape, the island and all its equipment are destroyed.
Doctor Doom bails three criminals out of jail and gives them new unique abilities. The team is indeed captured, but Doom ends up falling through spatial breach.
Mr. Fantastic and the Thing rescue Johnny and Sue who have been trapped by the Wizard.
The Fantastic Four are helpless against an alien who uses New York as his new playground until Reed realizes that he is but a child so he finds his parents that come to Earth to recover their Infant Terrible.
Ben complains he's doing all the work while the rest of the team is having a short discussion over a newspaper article about the X-Men.
Johnny asks his teammates not to interfere while he deals with the Plantman.
With the help of Doctor Strange, the Fantastic Four track down and recover the Invisible Girl who has been abducted by the Sub-Mariner.
The Fantastic Four send the Thing to hire Matt Murdock to review the legal aspects of their lease renewal while they leave for the capital to be awarded another medal, but when he fails to deliver his report the next day, they decide to hire someone faster.
Alicia tells Ben that she will stop seeing him because she does not deserve him, but he reassures her by saying that he thought himself was not good enough for her. The Fantastic Four are forced to surrender by the Red Ghost who leaves them stranded on the surface of the moon. After they defeat him in the Watcher's Citadel, the Watcher sends them back home.
The Fantastic Four get a few phone calls from J. Jonah Jameson who is desperately trying to locate Spider-Man.
Paste-Pot Pete's attempt to attempt to get revenge on the Human Torch falls short when he has to tackle the Thing first and then face the two heroes who send him back in jail.
In Transylvania, Fantastic Four discover the castle of Diablo who compels the Thing into freeing him from 100 years of captivity. With the promise to be permanently changed back to human form, the Thing accepts to serve the alchemist. After the Fantastic Four discover that his science is a fraud, the Thing forces Diablo to flee back in to his crypt.
Jealous of Sue and Reed' popularity, the Human Torch and the Thing act on their own to intercept the Sub-Mariner on his way to New York Harbor. Furious of being betrayed, Namor leaves while Reed arrives with Sue, explaining that the negotiation meeting he had arranged with the Sea Prince is ruined.
After the Thing has attacked the Human Torch while they were flying the Fantasti-Car, they both learn from Reed that he was under the Puppet Master's control. Reed deduces that the Mad Thinker was also involved. He submits the Thing to a device that causes the radioactive puppet to backfire on the Puppet Master and knock him out.
Disgruntled again over the leadership of the Fantastic Four, Johnny and Ben decide to strike it off on their own and compete in race, but Reed teaches them a lesson by capturing them both.
During a reception at the Latverian Embassy, Doctor Doom drugs the Fantastic Four so they fight each other. Given the illusion that he vanquished Reed Richards in a mental duel, Doom has no more interest in the Fantastic Four and leaves.
The Fantastic Four confront the Mole Man who has pulled entire city blocks underground, capturing the Invisible Girl in the process. When they go to her rescue and defeat the villain, Sue gets critically injured by an explosion. At the hospital, Johnny is shocked at the visit of his father whom he thought dead. Being the only physician able to save Sue, he is taken to the operating room and the surgery is successful.
Reed makes another attempt at curing Ben but the subject becomes amnesiac after the treatment, so he reverses the process to restore his friend's memory. When Sue and Johnny's father escapes from jail with super-powers, the Fantastic Four try to capture him without harming him. They eventually discover that he's the Super-Skrull and that Franklin Storm has been sent off the planet. Reed forces the aliens to trade the Super-Skrull with Dr. Storm. They send him back with a bomb and he dies shielding the Fantastic Four from the blast.
The Human Torch and the Thing get a visit from Quicksilver and the Scarlet Witch at the Baxter Building. Unaware that the mutants only came to seek advice, they treat them as criminals and the encounter turns into a fight. Realizing that going there was a mistake, the siblings leave.
Reed and Ben are cleverly set against one another by multibillionaire Gregory Gideon whose megalomania drove him to accept a challenge to destroy the Fantastic Four. But when Gregory's son Thomas and the Thing end up back in time because of a trap he set for the heroes, Gideon runs to the Baxter Building and confesses to the Fantastic Four. After they bring back Thomas and Ben, Gideon comes to his senses and decides to renounce his fortune.
The Thing calls the Torch to inform him that Yogi, Harry and Bull have escaped from prison. Searching for his friend, Ben finds him stuck to a railway track, at the mercy of the Terrible Trio. He saves the day by rescuing his partner and capturing the three villains.
News that the Avengers plan to overthrow the American government reach the Fantastic Four who offer their help to defeat them, but the Pentagon wants no super-heroes on the streets.
The Fantastic Four make a friendly visit at State University to attend a lecture from Reed. During the speech, the Thing discovers that the dragon-like creature they saw earlier has been brought to life by Diablo and is now attacking him. The fight is taken outside where the rest of the team try to stop the Dragon-Man. As Diablo attempts to destroy the team, Dragon-Man tries to protect Susan and both the creature and its new master end up at the bottom of a lake.
Ben figures out how Silver Surfer can break free of the barrier keeping him on earth.
Invited at the opening ceremony of a dam, the Human Torch and the Thing save the day when an indestructible bouncing ball of metal gets out of the Mad Thinker's control and smashes the dam.
After Reed and Sue's engagement party, the Thing and the couple are attacked and rendered unconscious by the Frightful Four. With his Anti-Grav Disks, the Wizard sends them floating adrift along with Alicia, but they are rescued by the Human Torch. The Fantastic Four are about to defeat their evil counterpart when the Wizard's ship explodes, allowing the Frightful Four to escape.
The Fantastic Four travel to the Skrulls' home world to get some closure on Sue and Johnny's father's death. They get caught in an internal conflict between Franklin Storm's murderer and the Skrull King. After they saved the life of his daughter, the king informs them that they no longer need to fear an invasion from his race.
While visiting a store with their girlfriends, he and Johnny come face to face with the Puppet Master who has designed a machine able to hold the Thing and an Ice Queen that can freeze off the Torch's flame. But the heroes manage to set themselves free and surprise the Puppet Master who falls under his new device and turns into a statue.
The Watcher sends Johnny and Ben back in time to stop Kang who has traveled to King Arthur's court to take over the Knights of the Round Table and alter the future.
The Frightful Four capture Sue Storm then lure the rest of the Fantastic Four on a remote Pacific atoll where they leave them stranded until an atomic Q-Bomb explodes. A moment later, the Fantastic Four are unconscious floating at sea, unconscious yet protected by the Invisible Girl's force field.
After turning to his normal human form due to the explosion of the Frightful Four's Q-Bomb, Ben Grim realizes that the Fantastic Four have all lost their powers and become vulnerable to their enemies. As the heroes are suddenly attacked by Doctor Doom who has taken over their headquarters, Daredevil intervenes and protects them from the villain. Despite Ben's reserves, Reed is forced to use his Power-Stimulator to change him back to the Thing. After defeating Doctor Doom by destroying his armor, the Thing announces to the team that he is quitting.
In the aftermath of their battle with Doctor Doom, the Thing has left the team, only to be captured by the Frightful Four who brainwash him to join their group and turn him against his former teammates. With his help, they manage to neutralize the rest of the Fantastic Four. But soon, Reed manages to abduct Ben and tries to cure him of his brainwashing. The Frightful Four attack Reed and Sue and use the captured Human Torch as leverage to have the Fantastic Four surrender. But having the Thing back on their sides flips the tide for our heroes and although Madame Medusa is able to flee, her teammates are delivered to the police.
While Ben Grimm greets the guests for Reed Richards and Sue Storm's wedding at Baxter Building, he realizes that an army of super-villains is trying to ruin the day with an assault on the Fantastic Four. Reluctant to alarm his best friend on his special day, Ben has no choice but to warn Reed that too many of their old foes have joined forces. Thanks to the Watcher, Reed uses a machine that transports all their enemies back to the recent past with no memory of what occurred. Finally, Reed and Sue are wed in front of all their family and friends.
Hearing that Doctor Doom has captured the Avengers, the Fantastic Four get underway to lend a hand but Washington won't allow them to interfere in case this would precipitate a diplomatic conflict.