Don spearheads a new campaign, Roger gets some unsettling news, and Betty takes in a houseguest.
Don clashes with a client. Pete entertains a guest. Peggy struggles to motivate the staff.
The Drapers get quite an offer, SCDP initiate Project K and Harry and Joan have a showdown.
Peggy plans for the future. Roger courts a potential client.
The client list at SCDP changes, causing some big ramifications for the staff, both personally and in business.
Things quickly become awkward after the two firms merge, Don asserts his dominance over Sylvia, Pete has to deal with his ailing mother, and Bob Benson helps out a sick Joan.
The creative department has a wild, drug-influenced weekend as they work on the Chevy account, Don has trouble letting go of Sylvia, and Sally walks in on an unwelcome intruder.
Peggy becomes unsatisfied with her apartment and with Abe. Don has an eventful weekend with Betty while Megan has problems on the set. Roger has time with his grandson, and Pete begins exploring his options outside the firm.
Cutler and Chaough prepare to make radical changes to the firm while Sterling and Draper are visiting a client in Los Angeles. Joan's decision to go after a new account on her own leaves Pete furious and frustrated.
Tensions rise when there’s a lack of communication at Sterling Cooper & Partners.
Ted and Peggy work really well together, while Pete goes looking into who Bob is and Sally goes looking at a boarding school.
With his personal and professional life crumbling around him, Don positions himself for a change of scenery. Meanwhile, Pete's life is falling apart as well, thanks to the meddling of Bob Benson.