The first part of Fringe's season finale aired May 5th. "Brave New World, Part 1" answered some questions, but raised others. As the episodes begins, Peter and Olivia are looking at the newspaper housing section. When Peter finds a house that sounds appealing, Olivia asks an important question. "Does it have a nursery?" Before the audience discovers if she's already with the child, the phone rings.
In another part of Boston, a man has just purchased coffee. He begins drinking it as he walks away. After a few feet, he stops. Smoke comes out of his mouth and he drops dead. Others around him begin doing the same thing. Unaffected people stop moving, realizing movement is the trigger.
When Olivia and Peter arrive to investigate, Walter is already there with Astrid. He quickly discerns the victims died of spontaneous combustion, but he doesn't know how. That's when a woman named Jessica calls to him. He notices smudges on her hand and concludes the infection could be viral.
It isn't. They soon find device tied into the escalator. Walter hypothesizes it released nanites into the victims through their skin. Jessica agrees to serve as a guinea pig for his cure. But she begins to heat up as Walter works. Olivia steps forward and grabs her hand, and suddenly her body begins to cool. It gave Walter time to complete the cure.
However, Walter tells Astrid the nanites weren't created by David Robert Jones, even though they know he set the device. He insists they are William Bell's. To prove it, he heads back to St. Claires to check the sign-in logs. Sadly, they don't back up his claim. There's no evidence that Bell visited him. Still, Bishop takes the log to his lab, determined to prove his claim.
Home again, Peter and Liv begin to unwind when they see a bright light outside. It looks like a laser beam directed near Beacon Hill. Agent Broyles sees it too and calls the team in to investigate.
Walter surmises the beam will heat an underground oil pool and start a fire that will destroy Boston. With Astrid's help he finds from where the beam originates and sends Peter and Olivia to turn off the supporting satellites.
In his hideout, David Robert Jones talks to someone viewers can't see. When his face is finally revealed, it's no surprise. It's William Bell. Referring to his chessboard, he tells Jones it's time to sacrifice the bishop. Jones heads off to kill Peter, reaching him just seconds after he and Olivia turn off the satellites.
Jones tries to infect Peter with nanites. However, from the building across from him, Olivia stops him by using her mind to direct Peter's movements. As Jones dies, he realizes he was the sacrificed.
Elsewhere, Walter discovers almond oil on pages of the log book. It's significant because Bell was fond of almonds. He and Astrid head off to the import warehouse where Bell imported them. When they arrive, they're told the business is defunct. The duo starts to leave but hears strange noises coming from another part of the warehouse. They go to check it out. What they find are mutants.
Astrid grabs Walter and runs for it, but it's too late. Security shoots at them, hitting Astrid in the stomach. As Walter bends over his dying companion, he hears a familiar voice saying, "hello old friend." William Bell steps out of the shadows.
Next week, the Fringe finale continues. It will set up the final season of 13 episodes which begins next fall.