FULL SPOILERS ahead for Dark Matter season 2, episode 9, "How To Build the Box."
Dark Matter season 2's penultimate episode, "How To Build the Box," ends in a pretty macabre fashion. That being said, it wasn't a totally unexpected climax. Furthermore, it expands the show's multiverse just a little more after the episode focuses largely on pre-established or familiar-feeling realities.
With Detective MacNamara (Chris Diamantopoulos) finally getting the breakthrough he's been so desperate for over the last two years, he finds himself standing in a new universe as Jason (Joel Edgerton) and Daniela (Jennifer Connelly) introduce him firsthand to the concept of the multiverse. However, MacNamara quickly learns his discovery isn't necessarily as positive as it might initially seem.

Dark Matter season 2's Apocalyptic Chicago has never been shown before episode 9
Dark Matter is no stranger to showcasing alternate realities that haven't been quite as fortunate as the more run-of-the-mill worlds. For instance, season 1 featured a Chicago that had already been almost completely destroyed by some unknown disaster, and another that was completely flooded and plagued with violent storms.
Other less desirable worlds include the one where a lethal virus continues to be battled by the CDC, although that one is still clinging to hope, fighting to keep everyone from dying. This potential for stepping out into horrifying worlds is what Jason and Daniela weaponize to get MacNamara out of the picture for good.
Under the guise of simply showing MacNamara the ropes, Daniela and the multiversal copy of her husband use their experience piloting the Box to land in a world that's deceptively alluring but, ultimately, will free them from being pursued and recaptured by Diamantopoulos' character. As such, they end up in a new Chicago just moments before being struck by a giant meteor.
I must say, the bait-and-switch was pretty genius. I initially thought that Jason was showing his captor the wonders of everything he had refused to share during his time as a prisoner. For a time, MacNamara did get to experience that thanks to the spookily high spirits and out-of-place attire on the beach. Unfortunately for him, his being caught up in the moment caused him to stray too far from the Box by the time he realized what was going on.

I can't help but feel like Dark Matter season 2 wasted Detective MacNamara
Dark Matter season 1 addressed a big plot hole that the 2016 Blake Crouch book never really tried to solve. In short, there had been a string of missing people who had vanished into the Box and never returned. Apple TV introduced Detective Jamie Mason (Kate Eastman) to pull on that thread, which led her to also become suspicious of Jason2's strange behavior. She never actually got all that far in her investigation, but at least she got the ball rolling.
Then, MacNamara and the Department of Defense were brought in for season 2 in order to further that subplot. I wasn't exactly sure how even an organization with so many more resources could get to the bottom of things, but I was excited to find out. So far, with just the finale left to drop, the DOD just...hasn't done all that much.
MacNamara seemed like a man worthy of cracking the case at one point, but other than a strong curiosity about the Box and an unrelenting need to understand it, he's now dead without being able to report back on what he's discovered. On the whole, he comes across as a pretty useless character who never delivered on the threat he was implied to pose. Even his multiversal counterpart from Retro Chicago is now just lost and stranded after Jason thrust him into the Box earlier in season 2.

Leighton's depressing epiphany is the most important part of Dark Matter season 2, episode 9's ending
Dayo Okeniyi's Leighton Vance is based on a character from the source material; only Apple TV's iteration massively expands his role in the story, even before season 2 premiered and took the show beyond the standalone sci-fi novel. The current batch of episodes has continued to increase his workload, making it clear that his desire to improve the multiverse via collaboration is why the Box was built in the first place.
However, despite being told numerous times by various versions of his Velocity colleagues, he's largely ignored the fact that his plan carries more risk than it does potential for benefit. So far, the negatives of certain universes have outweighed the positives of others. In other words, the endeavor isn't paying off, and it has taken Leighton until now to finally see that.
It remains to be seen if Leighton will openly admit that it's best to abandon the Pyramid and the idea of trying to create a network that connects the multiverse with the intent of improving the quality of life for its infinite number of residents. He's ambitious, driven, and stubborn, but he's not an inherently evil man. Plus, he surely can't ignore the fact that, throughout Dark Matter, multiversal travel has resulted in more harm than anything else.
Dark Matter season 2 is streaming now on Apple TV.
