Castle and Beckett wake up in bed together handcuffed to each other, and they have no idea where they are. Slowly, they piece together that they've been drugged and kidnapped. Beckett realizes his valuables are missing -- badge, gun, cell phone, etc.
Next, they try to remember what they were doing before being kidnapped. They recall going to a crime scene at a motel where housekeeping found a dead man in a room. Castle and Beckett discover the man's fingerprints have been burned off and he checked in under the name Jack Sparrow.
At the autopsy, Lanie tries to get more information on the victim while Castle presses her for information on what she and Esposito were fighting about at the crime scene. While in bed, Beckett tells Castle that Lanie and Esposito have tension because they're into each other but won't admit it.
Then Castle remembers that Lanie wanted to try and get fingerprints from a deeper layer of skin but that it would take a few days. In the meantime, Castle and Beckett traced the sender's address on an envelope in the victim's pocket. They get to the house and see an old woman kept in a cage. The next thing they know, they're cuffed to the bed, so they must have been drugged at that moment.
Meanwhile, Esposito and Ryan checked out the mailing address on the envelope. They become suspicious that something has happened to Castle and Beckett when they haven't heard from them. They find out the identity of the victim through partial fingerprints on the envelope and the body. The victim turns out to be a trucker named Hank Spooner. A DEA agent named Martinez has been looking for him because he suspects Hank is a drug smuggler.
Beckett and Castle try to escape from the basement they're in. While rummaging around, they find a trunk full of what looks like torture devices. At the same time, the team is in pursuit of Castle and Beckett. They also trace the tracking information on the envelope to find their way to the sender.
They eventually find Hank's abandoned truck and determine he was definitely smuggling something because all the boxes in his truck are empty. One of them must have had contained contraband and the empty boxes were decoys.
Becket climbs atop Castle's shoulders to bust through a hatch in the ceiling. Once open, they find that they are in a warehouse rather than the house they last remember seeing. Their captors see them and the two, still cuffed, try to hide from the. They suspect the captor's run a human trafficking ring, but once they hide out in a room, they discover they're actually trafficking tigers.
When Ryan and Esposito find the warehouse, they manage to save Beckett and Castle just in the nick of time from a tiger.