Spoilers for Season 2, Episode 9.

How do you build a machine capable of opening pathways to other realities? Dark Matter’s answer involves a sacrifice Jason still insists he can avoid. “How to Build the Box,” the penultimate episode of Season 2, brings the two central Jasons together again and confronts scientific obsession with its consequences for a family. As one explains what he sacrificed to complete his project, the other must recognize how closely he is following a similar path.

Meanwhile, Charlie finally finds Max, Daniela faces another version of her nightmare, and a plan emerges to end travel between universes. The possibility of shutting down the Boxes creates a tangible urgency: people are still searching for those they love on the other side of the doors.

Jason 2’s Warning

The episode returns to Jason 2’s visit to the man whose life he stole. His explanation of how he built the Box gives the title its meaning: reaching that breakthrough required absolute dedication, with everything else pushed into the background. It is a conversation about the human cost of scientific achievement.

For Jason, hearing this from his other self should be particularly uncomfortable. He knows the outcome of that choice because he was its victim. Even so, understanding the threat has not made him immune to the fascination that produced it. There is always a justification for continuing to work: protecting his family, understanding how the machine operates, preventing further intrusions. The problem is that the work progressively takes the place of the people he supposedly intends to protect.

Jason 2’s presence also undermines a comforting distinction. Being the husband Daniela chose does not guarantee Jason lasting superiority. He still has to choose how to live, and the suffering he has endured cannot make those choices for him.

Daniela Finds Another Jason in a Cell

While searching for Charlie, Daniela arrives in MacNamara’s world and is captured. Placed in a transparent cell with a Jason who has been imprisoned for two years, she must first establish whether he is her husband. Discovering that he is another version triggers panic: after everything she has experienced, that familiar face also signals danger.

MacNamara threatens to subject her to the violence he has already inflicted on the prisoner. Daniela, however, has managed to conceal two vials of the substance needed to access the Corridor. She offers to demonstrate how the Box works in exchange for their freedom, creating an opportunity to escape.

The encounter exposes one of the season’s most persistent wounds. For Daniela, recognizing Jason is no longer instinctive. His appearance no longer guarantees intimacy, trust, or protection. Every reunion requires an investigation, even when she is vulnerable and needs, above all, to be able to trust someone.

This Jason also carries a story that has continued beyond the family’s field of vision. While we followed other journeys, he remained imprisoned. The multiverse accumulates interrupted lives, and the series reminds us again that escaping a reality does not bring the events within it to an end.

MacNamara Opens the Wrong Door

Inside the Box, Daniela and the prisoner manage to drug MacNamara and take him into the Corridor. The agent opens a door and finds a beach party. The celebration, however, is taking place in the face of an imminent celestial catastrophe. By the time he recognizes the danger, Daniela and Jason have closed the passage, leaving him behind.

MacNamara becomes trapped by his own certainty that he understands enough to control the situation. For Daniela, escaping involves a brutal decision. She must act against the man threatening her, but the ease with which a door allows someone to be abandoned adds weight to their departure. Survival continues to demand choices that leave no one unscathed.

Charlie Finally Gets to Know Max

Charlie finds a reality in which Max received the heart transplant that saved his life when he was four. He explains to his brother that he comes from another universe, where the procedure never happened. Their growing connection also allows them to talk about the family and the fears Charlie carries about his parents.

It is an emotionally complicated opportunity. Charlie was searching for someone whose absence is part of his identity, but he finds a person with a life of his own. Max has grown up, had experiences, and exists beyond the longing of the brother who has arrived from another world.

There is something painful about the possibility of discovering who someone might have become. The encounter gives Charlie an experience he was denied, but it does not change his childhood. Nor does this Max’s existence erase the other’s death. What can change is how Charlie carries that loss — and how he understands the family he still has.

Blair Finds a Way to Shut Down the Boxes

Jason’s reunion with Amanda and Ryan, followed by Blair’s arrival, brings together the knowledge needed to formulate a solution. The plan involves reaching the original Box and inserting a shutdown command into its code. The theory is that cutting off the source on which the others depend could shut down the entire travel network.

The proposal gives the final stretch a concrete objective, but leaves a difficult question: when could they carry it out? With the Dessens separated, closing the passages could make that distance permanent. The technical solution requires a degree of human coordination the characters are still far from securing.

Leighton Sees What Came Through the Box

While searching for quantum computing components for the Pyramid, Leighton visits the world devastated by giant insects where Blair was trapped. Security footage reveals that the creatures arrived through the Box. The destruction of that reality is a consequence of interdimensional travel itself.

The discovery gives Blair’s warnings another dimension. Transferring knowledge and technology between worlds also means transporting threats. The promise of improving one reality with resources from another requires a level of control no one has demonstrated.

The episode thus leaves its characters facing incompatible desires. Charlie has found a deeply personal reason to be grateful that the Box exists. Leighton has seen a reason to fear it. Jason is searching for a way to stop the mechanism that continues to fascinate him, while Daniela is still trying to reunite the family.

Shutting everything down is beginning to seem necessary. Finding a way to bring everyone back first is the problem that turns that possibility into a threat.