Tonight on Fringe, an odd occurrence causes people to spontaneously combust and Walter Bishop must revisit a dark time in his past in order to save the day. Also, the Fringe Division comes face-to-face with ultimate season villain David Robert Jones.
After a crowd of people spontaneously combust in a busy Boston area, Walter discovers the use of nan-nites and takes one brave soul, Jessica Holt, back to the Harvard University lab to experiment. Here, Olivia assists in helping to keep the woman alive with a simple touch as her temperature begins to rise to extreme levels.
David Robert Jones, of course, is found to have planted the nan-nites, yet Walter believes that someone else was the mastermind behind them. Jones' boss is finally revealed. It is none other that William Bell, played by Leonard Nimoy, who suggests that a bishop must be removed from this real-life game of chess.
Walter, Peter and Olivia travel to St. Claire's Hospital after trying to convince Nina Sharp that her old lover is still around and causing havoc. At the hospital, Walter revists his old room and relives some painful memories, yet walks away with a notebook of hospital records.
Peter and Olivia call Broyles to the top of a Boston building to witness a beam. Yes, it's a sight to see. A beam shines down from above and focuses on a nearby building, destroying it from the inside out. Walter is called and the couple explains what they've just seen. He suggests that Jones has wired satellites to pick up frequencies of his choosing. They attract the reflection of the sun, creating a beam of light that has the power to destroy as previously seen. The two travel to the sight of the satellites, unknowingly with Jones on their tracks.
Once the satellites are switched off and the beam disappears, Jones starts a fight with Peter. Olivia pulls her gun, but police arrive and make her drop her weapon. She instead uses her powers to remotely control Peter's movements and fight back. Jones falls to the ground and says, "I was the sacrifice. I was the bishop." With that, he dies.
Meanwhile, Astrid has reluctantly followed Walter to a warehouse as he is looking for more proof that Bell is behind all of this. Instead, the two find men equipped with guns. Astrid puts up a great fight and, pulling Walter behind her, runs through a maze of storage trailers. Sadly, a bullet catches up to Astrid and she falls to her knees. Walter sobs, holding her in his lap as Bell walks up to them, laughing. He thought he would never see Walter again.
"We do know Jones. We know he's not going to just give up."
"The most valuable piece is the Bishop."
-- William Bell
"Nina! It was the work of a master, not an imposter!"
"I must say, you're much prettier than your predecessor."