Dark Matter recap

Chicago physics professor Jason Dessen is abducted and sent through a quantum device into a reality where he became a renowned scientist instead of marrying Daniela and raising their son, Charlie. His alternate self built the device, found Jason's happier domestic life, and stole it. Jason escapes into the device's corridor with psychologist Amanda Lucas, learning that each door opens onto a world shaped by possibility and the traveler's mental state. After dangerous failures, he reaches his own Chicago and exposes the impostor to Daniela. But every choice Jason made in the corridor produced further versions of him, and many also arrive seeking the same family. Jason, Daniela, and Charlie flee a growing conflict among the alternates. The other Jason eventually helps them reach the box with a supply of the drug needed to use it. Together they leave their original reality, and Charlie chooses the new world, giving the family a chance to begin again beyond the rival Jasons' reach.

Jason Dessen lives in Chicago with his wife, Daniela, and their teenage son, Charlie. He teaches physics at a small college, while Daniela has largely set aside her art. Both once had greater professional ambitions, but their family remains the center of Jason's life. After celebrating former colleague Ryan Holder's major science award at a neighborhood bar, Jason is abducted by a masked man who seems unusually familiar with him. The stranger forces him to drive to an abandoned industrial site, makes him strip, and injects him with a drug after asking whether he is happy with his life. Jason loses consciousness and wakes in a sealed facility, surrounded by people celebrating his return. They know him as the brilliant leader of an experiment he has never conducted.

At Velocity Laboratories, chief executive Leighton Vance and psychologist Amanda Lucas treat Jason as the physicist who created their secret project and vanished inside it. Jason escapes and seeks Daniela, only to find that in this reality she never married him and Charlie was never born. Here Jason abandoned their relationship to develop a quantum superposition device: a person rendered unconscious to observation can enter a sealed box and move among possible worlds. The masked abductor was another Jason, the successful physicist from this reality, who used the box to find the life he regretted surrendering. He exchanged places with Jason so he could live with Daniela and Charlie. Velocity recaptures Jason, but Amanda accepts that he is not the man she knew and helps him flee into the box's seemingly endless corridor.

Jason and Amanda have a limited supply of the compound that allows the mind to enter superposition. Each door in the corridor can open onto a different version of Chicago, but their fears, desires, and subconscious expectations influence the destination. Their first attempts lead to lethal or devastated worlds, including a city overwhelmed by epidemic and another locked in extreme cold. They learn that merely wishing for home is insufficient: Jason must identify the precise life he lost without allowing panic or nostalgia to distort it. Amanda's training helps them remain deliberate, while Jason's fixation on Daniela and Charlie makes navigation harder. Meanwhile, in Jason's original world, the other Jason assumes his place and begins reshaping the family around the choices he wishes he had made.

Looking for guidance, Jason and Amanda find a version of Velocity scientist Blair Caplan who survived an expedition into the box but refuses to reenter it. Her experience confirms that travelers bring their mental condition into the selection of worlds. Continuing alone, Jason and Amanda encounter realities that are appealing but not truly theirs. In one, Jason finds a fulfilled family life with Daniela, only to learn that the version of him native to that world has recently died. He cannot accept happiness that belongs to another man's history. Amanda eventually chooses to remain in a prosperous, peaceful world where no counterpart of hers appears to have lived. She gives Jason the remaining ampoules so he can continue searching for his own Daniela and Charlie.

Jason refines his understanding of the box and at last reaches the Chicago he recognizes. Months have passed since his abduction. The other Jason has used wealth and confidence to change the family's life while isolating Daniela from people who might notice differences, including Ryan. Jason contacts Daniela secretly and gives her details that convince her he is the husband who disappeared. She drugs the impostor long enough to escape with Jason and Charlie. Their reunion does not end the danger. Jason begins encountering other versions of himself, men whose paths diverged during different choices in the corridor. They share his memories up to the abduction and many have endured terrible worlds to return. Each claims the same identity and family, and some are willing to kill the others.

Jason hides Daniela and Charlie while numerous alternate Jasons converge on Chicago and fight over the family they all remember. No test can establish one uniquely genuine husband: the rivals share the same past and branched only after entering the box. Jason recognizes that Daniela and Charlie must be allowed to choose, and they choose to remain with him, but the family cannot safely stay in this reality. The other Jason, whose original theft caused the crisis, ultimately provides access to the box and the ampoules required for travel, helping the family get past the pursuing alternates. Jason, Daniela, and Charlie enter the corridor together. Jason refuses to impose another destination shaped solely by his own longing and asks Charlie to choose their new world. Charlie opens a door onto a quiet, welcoming reality, and the three step through together, leaving the contested Chicago behind.

Jason finally reaches the Chicago he came from, but the physicist who abducted him has been living as Daniela's husband and Charlie's father. After Jason convinces Daniela of the truth, they flee with Charlie. The situation expands beyond a contest between two men: many versions of Jason have reached the same world, all branching from choices made by the abducted Jason while navigating the box, and each believes he is entitled to return to his family. Violence among the alternates makes remaining in Chicago impossible. The other Jason ultimately gives Daniela and Charlie the means to escape and helps hold back the competing versions. Jason, Daniela, and Charlie enter the box together. To avoid making the destination another expression of Jason's desires, Jason lets Charlie choose and imagine the world they will enter. The family steps into a peaceful new reality, leaving their original world and the surviving alternate Jasons behind; the exact future awaiting them remains unknown, but they face it together.