In season eight of Blue Bloods, Det. Danny Reagan (Donnie Wahlberg) deals with the aftermath of a tragic accident involving his family, and NY Police Commissioner Frank Reagan (Tom Selleck) clashes with the new interim mayor. Also, officers Jamie Reagan (Will Estes) and Eddie (Vanessa Ray) are back as partners when they test the waters going undercover, and NY Asst. District Attorney Erin Reagan (Bridget Moynahan) continues to serves as the legal compass for her siblings and father. Lorraine Bracco guest stars as the new mayor, Margaret Dutton.