Back at the FBI, Mark's on Project Annabel Lee, and he's off to canvass the area where the van was last spotted. Simon wants to come along, but Mark rips a strip with "You're here to work on the QED. Your volunteering here is starting to feel a little convenient. I don't trust you, Simon, not for a minute! Right now, I'm going to get your sister back, and after I do, you and I are going to have a little sit-down. No more lying." Cut to Simon quietly panicking over the prospect of Mark biffing everything. Then he goes into the lab, tries to log into his FBI computer, and discovers he's been locked out of the laptop. For some reason, this seems to be what makes him decide to take off with the QED. Yep -- totally not comfortable unless he's feeling aggrieved by someone else.
Demetri and Fiona are now chasing down leads on who killed Andy. They go to the coffee shop where Andy bought his fatal brew and the barista -- or is it baristo? I'm never sure if these romance-language-derived terms should be gendered or if I'm overthinking it -- anyway, the male barista mentions that Andy was with "some tall, geeky-looking dude who had a really ugly horseshoe ring." Like the seasoned, detail-absorbing law-enforcement professionals they are, Demetri and Fiona both recall that Slingerland was wearing a righteously ugly diamond-studded horseshoe ring.
We cut to Slingerland telling his class, "'You can do what you will, but at any given moment of your life, you can only will one definite thing. Nothing other than that thing.' What do you think that means?" A student guesses, "That free will is a lie?" Slingerland's smiling at that until he catches sight of Fiona and Demetri coming up the walk, and he says, "Exactly," right before taking off. A student tells Demetri, "He wanted me to tell you something: the universe always pushes back." Demetri and Fiona recall Slingerland wryly asking, "You don't want me to go on TV and announce that I'm still alive?" and then they recall Celia going on TV to talk about how the universe obviously planned for her to still be alive. And the penny finally drops: Slingerland's going to gas up his car and go tooling around the streets of L.A. until he finds Celia.
Sure enough, in the next scene, it's dark and Slingerland's starting the car. He says happily, "Celia Quinones, welcome to your future." Except that Slingerland's future holds a surprise -- Demetri barreling an FBI sedan right into Slingerland's station wagon as Slingerland turns on his headlights. Celia looks ...well, like a deer caught in the headlights. Demetri opens up his car door and bellows for Celia to run. She does... down the center of the road. And that is how Fiona ends up hitting Fiona at a decent clip. It's totally an accident, but still... it's a pretty bad accident. Also, somewhere in the melee, Demetri ended up taking Slingerland down and the tackle is apparently fatal. His last words are to Demetri: "See you soon, sport." Demetri is understandably freaked out. And, one thinks, probably very open to the idea of multiple universes right now. Time to find a mad scientist to send him to the one not intent on killing him!