Gonzalo Vargas

Danny and Baez investigate a homicide in which Baez's estranged brother, a former drug addict, is the lead suspect. Meanwhile, Frank learns one of his most highly decorated officers, a German Shepherd in the K9 unit, is being accused of police brutality, and Henry investigates the widow of a former NYPD pal who might have had a hand in her husband's death. Kirk Acevedo guest stars.

Lindsay (Sophia Bush) has her first case with the task force and realizes she needs to call on Voight (Jason Beghe) and the Intelligence unit to assist. Meanwhile Burgess (Marina Squerciati) is back on the job, but relegated to desk duty which allows Desk Sgt. Platt (Amy Morton) the opportunity to partner up with Roman (Brian Geraghty).