This season of AMC’s “Mad Men” is one of the most enjoyable — if hard to predict — because you never know what’s going to happen next. In any given episode, Don Draper might be choking an old fling — at least in the depths of a fever dream — or Lane Pryce might be handing young Pete a beat down.

In tonight’s episode, “Far Away Places,” the plot was appropriately odd and disjointed, especially considering all the sex, drugs and rock and roll.

The show continues its headlong plunge into the heart of the most turbulent part of the 1960s as Peggy (Elizabeth Moss, who is always wonderful) gets fed up with the Heinz beans people and insults them, much to everybody’s shock. So Peggy, who earlier had an argument with her boyfriend, decides to take in a matinee.

Peggy gets offered a joint by a guy (in very loud striped pants) in the theater and doesn’t react with dismay when he makes a pass. As a matter of fact, Peggy administers an “Animal House”-style handjob — minus the Greg Marmalard plastic gloves — right there in the theater.

Meanwhile, Roger (the likewise always wonderful John Slattery) and wife Jane (Peyton List) go to a party and partake of LSD. The middle part of the episode finds Roger and Jane tripping out. When they come around, Roger tells Jane he’s moving out, a decision based on her acid-inspired comments.

Also meanwhile, Don (Jon Hamm) and Megan (Jessica Pare’) go out of town on a trip to a Howard Johnson’s. It’s ostensibly to check out a client, but Don plans the same uncomfortable mixture of business and pleasure that he’s been practicing with Megan all season. When they get into a fight and Megan disappears, Don’s anxiety skyrockets.

To top it all off, Bert Cooper (Robert Morse) — who’s spent how many seasons wandering in the wilderness of the conference room? — administers a brisk slap across the face to Don. Bert calls him out on how little work he’s done lately. Holy crap!

Other highlights:

I’m enjoying the little glimpses of Ginsberg and his father (“I’m the original,” the elder Ginsburg tells Peggy) but I’m curious where the characters are going.

Has “Mad Men” been employing flashbacks? Tonight we get a glimpse of the past in Don and Megan’s Disney vacation with Sally and the little Draper boy, whatever his name is.

In the preview for next week, Roger says he’s had a life-changing experience. Does he mean the acid trip? At the end of tonight’s episode, he was pretty damn cheerful.

“Mad Men” continues to keep us guessing.