Alan Pape, a longtime veteran of the police department, is hired by Tom Davis to run a lucrative private-security operation in Summit. After a break in Olivia's case, Eric's sister Petra queries Summit police officer Nate Henry about alibis, and heads to Louisiana to track down Joel, who's relocated there with Laura. Reluctantly, he agrees to return to Summit with Petra, and ends up scouring the local bars in search of a mysterious intruder.

Joel's New Year's Eve whereabouts come under increased scrutiny after his bar buddy Frank admits to Nate and Petra that their alibi was bogus. A visit to a New Year's reveler clears up one issue, but the timing of another remains unclear.

Though he has suspicions that the wrong man is in prison, Nate faces major obstacles as he tries to get a subpoena on a closed case. Eric is dogged by allegations stemming from an earlier mysterious death. An increasingly paranoid Joel weighs his options as evidence against him mounts.