Josh Salatin

Danny contemplates retiring until Erin enlists him to help her with a case involving her ex-husband, Jack (Peter Hermann). Also, Jamie and Eddie go undercover as a couple, and Frank butts heads with the new mayor of New York City, Margaret Dutton (Lorraine Bracco).

When Sherlock's brother Mycroft makes a surprise return to New York, his motivations cause discord between Sherlock and Joan. Meanwhile, a missing person case takes Sherlock and Joan inside the world of unmanned aeronautics. Rhys Ifans guest stars as Mycroft Holmes.

Carrie is thrilled when the junior-senior lock-in provides the perfect cover for a night out in Manhattan with Larissa and her Interview co-workers - until a surprising encounter turns her night upside-down. Maggie and Mouse confront Sebastian about his feelings for Carrie and tell him he better make a grand gesture if he stands any chance of winning her back. Harlan (recurring guest star Scott Cohen) finally convinces Tom to go on a double date, with surprising results. Meanwhile, Maggie tries to find the courage to tell Walt about Simon (recurring guest star Josh Salatin) before Donna LaDonna does.

As his power over the Korban cult grows, Joe sets a deadly plan in action using new acolytes to carry out his demands. Meanwhile, Ryan and Max devise a plan to contact Joe, in hopes of tracking down his whereabouts; and Weston meets with a face from the past.

Larissa returns from her summer in Kyoto and insists on taking Carrie and Walt to a fabulous Japanese festival in the city, where Larissa meets Samantha, with an explosive result.