NOTE: This spoiler was submitted by Jeremy
Young Reed Richards does a presentation for his class and states that he wants to be the first person to teleport through dimensions. His classmates laugh at him and his teacher mocks his goal, but Ben Grimm takes an interest in Reed's words.
Later that night, Reed sneaks into Ben's family's junkyard and gets him to help him bring a device into his basement. Reed gets a toy car and attempts to show Ben that teleportation is very real. He activates his machine and fries every transformer in the neighborhood, but he manages to teleport the car and sees a pile of rocks where the car used to be. Ben tells Reed he's insane.
Seven years later, Reed (Miles Teller) and Ben (Jamie Bell) are best friends entering a science fair to show off their machine. Reed teleports a kid's model plane but causes an energy surge that breaks a basketball net, disqualifying him. He and Ben are approached by Dr. Franklin Storm (Reg E. Cathey) and his adopted daughter Sue (Kate Mara). Impressed by Reed's invention, Franklin invites him to join him in a project at the Baxter Foundation. Ben later gives Reed his old pocketknife as a going-away present.
Franklin speaks before a board of other researchers headed by Dr. Harvey Allen (Tim Blake Nelson), who isn't too eager to put young scientists on this project. Franklin wants to use interdimensional travel to acquire new resources that can be used on Earth. He later goes to see out Victor Von Doom (Toby Kebbell), as he is the one that started the project. Franklin finds him in a shack and urged him to go back and work with him, despite Victor being rejected before. Victor only agrees because he has a thing for Sue.
We meet Franklin's son Johnny (Michael B. Jordan) in a street race. He initially stalls out but catches up and puts the pedal to the metal...until his car blows out. Franklin finds Johnny in the hospital and scolds him for wasting his potential, but Johnny resents his dad for putting more focus on his work than his family.
Johnny joins the team and quickly befriends Reed. Victor is cold and snobby towards them, but the whole team works together and creates a bigger teleportation machine based off of Reed's designs, known as the "Quantum Gate". After the machine is complete, the team sends a little chimp through the other dimension, which they call "Planet Zero." They receive video surveillance of the planet, and they successfully bring the chimp back in one piece. Allen then tells the team that he and the other board members will be recruiting NASA members to be the first human subjects to travel to Planet Zero, despite Franklin trying to convince Allen that the team is ready.
Reed and Johnny share a drink with Victor as they lament this news. They decide that they're gonna go ahead and teleport themselves anyway. Reed calls Ben and invites him to join them.
The four guys suit up and teleport themselves to Planet Zero. Sue picks up a notice that the Quantum Gate was activated and she calls Franklin to the lab. On Planet Zero, the guys find soil and a green substance that reacts to organic matter. It starts to turn in a bad way and then causes an eruption. Realizing the place is unstable, the guys run back to the Quantum Gate. They climb back up a hill, only for Victor to be hit by a lot of the substance, causing him to fall into it. The other three run back and contact Sue, but Ben's pod gets filled with rocks while Johnny gets hit by a big ball of fire. They're teleported back, bringing a wave of radiation with them that hits Sue as well, making her partially invisible. When Reed comes to, he crawls over to Ben as he calls for help beneath a pile of rocks. Johnny is unconscious and completely on fire. Reed then sees his leg has stretched to an unnatural length and he faints.
Reed awakens to find himself strapped to a bed with his limbs stretched out. He repeatedly asks for Ben but none of the doctors answer him. When they leave, he removes the straps and crawls through the air vents as he hears Ben calling for him. When Reed finds him, he sees Ben has been mutated into a huge rock creature. He begs Reed for help, but Reed hears people coming. He promises Ben he'll be back for him, and Reed escapes.
A year later, Allen has used Ben as an asset in warfare due to his size and strength. He is seen smashing tanks on the field. Johnny has managed to control his fire and flight powers, while Sue is exercising her invisibility and force field powers. Both have been given suits to accommodate these powers. Meanwhile, everyone is still looking for Reed. Sue tracks the pattern of the last few places he's been spotted. She gets a reading by tracking his emails, recognizing "cptn_n3mo" from when they talked about "20,000 Leagues Under The Sea."
Reed is in South America, able to disguise himself by altering his facial features. He detects that the airbase is breached and he is found by some mercenaries. Reed avoids their attacks by stretching and escaping, but Ben catches him. Feeling betrayed by Reed for abandoning him, he headbutts Reed and has him brought in.
Reed is taken to Area 57. Allen tells him that he wants Reed to help reactivate the Quantum Gate, and they may be able to find a cure from Planet Zero. Reed reluctantly agrees to help his friends.
After some time, Reed is reunited with the other three and a group of explorers re-enter Planet Zero. They detect a life form in the distance. It's Victor. The explorers bring him back and see his whole body coated in metal, a result of his suit fusing with him and the green substance. Victor awakens and says that he has grown stronger on Planet Zero and feels that he must destroy Earth to recreate Planet Zero in his own image. He starts to manipulate the objects in the room and kills a couple of doctors before blowing up Allen's head. Victor breaks out and continues blowing up heads before getting back to the Quantum Gate. Franklin tries to stop him, but Victor fries him. Before dying, Franklin tells Sue and Johnny to look after each other. Reed, Sue, Johnny, and Ben run after him and follow him through the Gate.
Everyone is back on Planet Zero. Victor has opened a black hole absorbs Earth matter and destroys it. The four realize they need to take him out in order to take out the portal. Victor continues manipulating the environment against the four, pinning them down. Reed tells them that he may be stronger than each of them, but not all of them together. Sue maintains a force field on the portal briefly while Reed distracts Victor. Ben declares, "It's clobberin time!" and punches Victor into the path of the black hole, absorbing and destroying him. Johnny then manages to close the portal while he flies and Sue brings herself, Reed, and Ben back to Earth.
The military, while hesitant to continue working with the four, reward them for saving the world and agree to give them a private base of operations. Reed decides the team needs a name. Ben admires the place and comments that it's fantastic. And suddenly, Reed knows what to call the team.