Matthew Del Negro

A temporary chief fills in for Boden, who is forced to take some time off for personal reasons; Lt Severide deals with an unwelcome addition to the squad; Brett becomes close to a girl she previously rescued; Casey starts seeing a new woman.

House 51 comes under investigation for negligence after Interim Chief Pridgen makes a grave tactical error during an apartment fire.

Tony continues to haggle with Johnny Sack and the two Carmines over the Esplanade profits; Carmela makes a decorating date she can't keep; Furio proves a reluctant companion to Tony on a casino junket; Paulie plays an impatient chaperone to some ladies from the nursing home; Meadow debates the true meaning of a literary classic with her mum.

Jane searches for a way for Maura to find her biological mother, Dr Hope Davis. Angela gets swept up in a political campaign.

Paulie takes pains to integrate his mother Nucci into the social world at Green Grove; Furio faces up to his inner feelings during a trip to Italy to see his ailing father; Ralph introduces Tony to his new goomar, Valentina; Carmela finds a new source of investment income.

The BAU travel to Philadelphia where the latest victim of The Replicator has been found murdered.