Ed O'Neill and David Strathairn star on the premiere of this epsiode, following the clashes and cautious cooperation between NYPD detectives and FBI agents when their cases converge. In the opener, Special Agent William Preecher (Strathairn) deputizes a resentful Det. Mooney (O'Neill) and his partner, Vincent Trout (Jeffrey Pierce), when their murder investigation threatens an FBI sting operation aimed at the Russian Mob.
As Mooney (Ed O'Neill) adjusts rather uneasily to his recruitment into the FBI, he and Trout (Jeffrey Pierce) take part in a joint FBI-NYPD sting in which the outcome is overshadowed by an incident that leaves Trout shaken.
A Bureau administrator (Dylan Baker) visits the New York office, where it's clear there's some ill will between himself and Preecher, and he puts Sarah (Kim Dickens) in the middle. Meanwhile, Mooney may be getting close to having Klein give up some information on the stripper murder.
Flynn wires Corelli (Peter Appel) and sends him back to the Russians, with Mitya (Pasha Lychnikoff) in on the cover. Meanwhile, Mooney takes his sister to the planetarium.
Angered over Preecher's partial disclosure of information and his sister's failing health Mooney (Ed O'Neill) returns to the 11th precinct and takes Trout with him. Meanwhile, Preecher makes a serious decision about Maddock's arrangement with the Bureau.
Mooney's sister dies, and Preecher (David Strathairn) comes to the 11th to ask Mooney to return to the Bureau. Preecher also offers Mooney valuable information and reaches out to him in his grief.