At the Harvard lab, the Fringe team calls Phillip Broyles for help in finding out where the Observers took Michael. Broyles bluffs a Loyalist lieutenant, saying that Captain Windmark wants his division to help guard the prisoner and deflecting suspicion by joking that he is not The Dove (although he is).
Windmark is holding Michael in a lab on Liberty Island, where the Statue of Liberty has been destroyed. He tries to mind-probe the boy, but all he gets is a nosebleed and broken blood vessels in one eye. Interrogation over.
Broyles calls Peter, Walter, Olivia and Astrid with the news about Michael's location. The lab is heavily guarded, so Olivia suggests an end run: She'll cross to the Other Side, go to Liberty Island, cross back to This Side, grab Michael, cross over again, then cross back home in a safer location.
Since all the Cortexiphan burned out of Olivia's system after she regenerated (Season 4, Episode 22, "Brave New World: Part 2"), she needs a massive dose of the drug to restore her abilities. Luckily, Walter stashed some in the basement. Peter objects, arguing that they have no way of knowing whether the Observers also invaded the Other Side. Astrid says not necessarily and points to the dusty universe window.
They set up the window in Battery Park . . . and see an intact Statue of Liberty on the Other Side.
September/Donald arrives at the deserted lab with the other equipment they need. He builds the device, but when he plugs in the triggering mechanism, it has barely any power left.
In a resistance safe house, Walter gives Olivia multiple doses of Cortexiphan. While waiting for it to take effect, he almost tells Peter that the plan requires him to sacrifice himself - but doesn't.
Olivia only has about three hours to rescue Michael. With every jump, her system will burn up a lot of Cortexiphan. If it burns too fast, she may have withdrawal symptoms such as disorientation and lapses in time. They take her to the location of Fringe Division on the Other Side, and she crosses over.
Soon she's reunited with Bolivia and Lincoln Lee, who still work for Fringe Division and are now a couple with kids. They look great for their age. (Lincoln later tells Olivia that Walternate is still lecturing at age 90.) Olivia explains her need, and they take her to Liberty Island.
Windmark reports to the Commander. Anomaly XB-6783746 has capabilities they are unable to comprehend, and he believes the fugitives intend to use it to destroy them. The Commander wants to study the anomaly further, but to be safe, he orders Windmark to disassemble it first.
Olivia crosses back to This Side's Liberty Island. Disoriented, she's nearly subdued by an Observer but uses her pyrokinetic ability to distract him. She rescues Michael, but when they return to the Other Side, a few Observers follow! Lincoln holds them off while Bolivia takes Olivia and Michael to Battery Park, where they cross back home.
Questioned by Windmark about the security breach, the Loyalist lieutenant says Broyles lied about being authorized to join the detail.
September visits December, his old colleague. He needs a favor. "You owe me," says September. After a moment, December lets him in.