After Uhura is beamed out and the transporter craps out, Chekov is detained by security on the aircraft carrier. He's interviewed by an FBI agent later, who has his phaser and communicator set on the table in front of him. Chekov grabs the phaser and tries to shoot his way out, but the radiation from the carrier's reactor keeps it from working. He tosses it at the FBI agent as a distraction, and makes a break for it. The last time we saw the phaser, it was in the agent's hand, and the communicator was on the table.
