While dropping off a piece of evidence for analysis at the FBI, King (Jon Tenney) and Maxwell (Rebecca Romijn) get locked in the federal building when a key whistlebower is killed on Rigby’s (Michael O’Keefe) watch only hours before his testimony would have taken down the CEO (Derek Green) of a chemical manufacturer that poisoned the water supply of a small town. As the pair of detectives help Rigby hunt down a killer inside the FBI, Benny (Dichen Lachman) and Edgar (Ryan Hurst) work to find a second whistleblower in less than six hours to save both the case and Rigby’s career.
The investigation inside the building yields a disgruntled evidence worker with a sizable debt and a plastic gun created from a 3D printer (a nice touch). However, both their killer and Rigby are shot on the way to the courthouse. With Rigby pulled from the case, but unwilling to let things rest, he decides work with King and Maxwell to deliver to new witness to the courthouse whether his ass of a boss wants him to or not.
Although “Locked In” never makes a good argument for why Rigby’s boss is so willing to let the case die (I half-suspected him to be implicated in the woman’s testimony), the situation does force the FBI agent to rely far more on King and Maxwell than he’s comfortable with. King is shocked to finally learn that Maxwell has a chance to return to the Secret Service and we also get more of King’s continued investigation into the assassination including the detective lifting an FBI ID in hopes of getting a better look at the evidence packed away in the FBI archives.