Erin is overwhelmed with guilt after a man she set free is accused of killing a cop. Also, Frank and Mayor Poole continue their game of political chicken over Frank’s reappointment as commissioner, and Danny and Baez investigate a case of a cop who has gone AWOL.
Elenco: Tom Selleck , Donnie Wahlberg , Bridget Moynahan , Will Estes , Len Cariou , Sami Gayle , Marisa Ramirez , Abigail Hawk , Vanessa Ray , Gregory Jbara , Robert Clohessy , Andrew Terraciano , Amy Carlson , Jennifer Esposito , Steve Schirripa .