When Jake visits the Captain's office with a lead on a jewelry store robbery case, he explains the crime scene matches the M.O. of a criminal, Dustin Whitman, that he put in prison two years ago who just got out. Jake tells the Captain that he has security camera footage which shows a male suspect of similar build to Whitman, and that crime techs are still at the scene. After Jake tells the Captain he's 100% sure it's Whitman, Captain Holt says they'll see what kind of physical evidence turns up and then they can talk arrest. Jake then tells the Captain he's already arrested him, so the clock is ticking on their fourty-eight hours to find the evidence.

When the whole squad are called into an emergency meeting, the guys are angry at Jake after they learn they will have to spend their weekend finding evidence to support Jake's arrest. After the emergency meeting, Captain Holt wants to send Terry home as he's tired after working a double shift. 

In the bullpen, Rosa wants to order dinner from Flatbush Diner as they make the "best pies in New York City." Gina disagrees and believes Crust has the best pie in the city. Rosa and Gina get Boyle to settle their culinary dispute, but he's torn because he doesn't want to disappoint Rosa. Meanwhile, Captain Holt finds Jake pulling faces at the suspect through the one-way mirror. The suspect knows Jake only has 48 hours to make the case stick.

The next morning, Captain Holt wakes the squad after they slept at the precinct. While everybody looks rough after crashing at their desks, Rosa walks in looking fresh as she's the only one lucky enough to live nearby. Jake leads a briefing to tell the squad their warrants finally went through. They need to place Whitman at the crime scene and prove he either possessed or sold the diamonds. Jake takes another crack at breaking the perp, annoying him by talking while playing a guitar.

Jakes goes to the Captain's office to ask him to send the rest of the squad home. When Holt asks Jake if he's still sure Whitman did it, Jake says he's positive. Captain Holt says the whole squad will stay so they have the best chance of putting him away.

Jake gets the suspect's bank records from Amy, who is happy she didn't reschedule her date for this evening since it doesn't look like they're ever getting out of the precinct. Jake tells her to reschedule her date for tonight, insisting he'll get them out of there in time. When Amy talks to Rosa and Charles about her upcoming, she says dinner and movie is the perfect first date, but Rosa and Boyle disagree.

Rosa and Boyle say they didn't manage to find any prints at the crime scene. Despite not needing to work this weekend, Gina comes in to the office with two pies for the squad to sample. Meanwhile, Terry goes to Captain Holt's office for him to sign paperwork. When a tired Terry clearly stifles a yawn, the Captain urges him to go home.

Jake tells Amy he's got the perp dead to rights, so she should go and prepare for her date. Boyle ranks the pies and tells Rosa hers is the best. Terry is upset that the squad are performing a pie tasting with just one guy. Terry suggests everybody has to try all the pies from both places, which will take a while. When Jake shows the suspect a debit card statement which puts him near the scene at the time of the crime, Whitman lawyers up. When Amy returns to the bull-pen in her dress, she accidentally sits down in one of the pies.

Terry, Rosa and Boyle continue their pie testing contest when Gina arrives with more pies. When Captain Holt orders Sergeant Jeffords to sleep, Terry says he can't sleep without whale songs. Terry doesn't want to go home as his brother-in-law, who mocks him for being a weakling, is in town.

Whitman's lawyer arrives and is furious with Jake for ruining his weekend. The lawyer says Whitman has an alibi: he was at Torque, a nightclub in Cape May, New Jersey, all night. Jake thinks the lawyer is trying it on, since it would take Jake six hours to drive to the Jersey Shore and back to check on the alibi. Either way, the lawyer says he walks in ten hours. Captain Holt orders Jake to go check out the alibi, but Jake stays behind to watch security cam footage, sending Scully in his place.

Boyle admits to Gina that her pie was better, but he wanted Rosa to like him. Gina says women don't usually like liars. Meanwhile, Amy and Jake continue watching the security cam footage. Amy tells Jake that her date never called her back after she canceled on him.

Scully returns to the precinct with the news that Whitman's alibi checked out. Holt and Terry are depressed about the case, but Terry is more concerned his brother-in-law is coming to the precinct to have dinner with him before leaving for the airport.

Jake tells Amy he called her date and explained how this weekend was entirely his fault, so he agreed to meet up with her tonight. When Jake explains how he knows a lot about the squad after being locked-in with them for 48 hours, he realizes "locked-in" is the clue. A former cell-mate of Whitman's robbed the store, after being coached by Whitman, and they agreed to share the loot.

Boyle goes to Rosa to tell her he was lying about her pie being better than Gina's. Charles has bought the best pie in New York City, from Argo's bakery. Rosa takes a bite and agrees it's amazing. As the squad finally leaves to go home, Boyle offers to buy them all a drink. The squad are not impressed, so Jake agrees to cover a shift for each of them.

When Terry's brother-in-law arrives and belittles him in front of the Captain, Holt lies about the case to make Terry seem more impressive and get him out of the dinner. Captain Holt then lets Terry crash on his couch - he even downloaded some whale songs.