Erin pleads with Danny, who has been contemplating retirement since Linda 's death in a rescue helicopter crash, to help her with a case involving her ex-husband, Jack (Peter Hermann) who 's been attacked in his office. Jamie and Eddie go undercover as a couple to bust a shady drug dealer; new mayor Margaret Dutton (Lorraine Bracco) butts heads with Frank.
who plays the current mayor on blue bloods
Lorraine Bracco