Actor James Wolk, who plays Bob Benson on Mad Men, told Rolling Stone that he received a phone call immediately after the end of season 6's 11th episode, after he was seen nudging the knee of Pete Campbell.

"It was my mom. She was totally shocked," the actor said.

Since his character mysteriously appeared in the elevator with Don -- and everywhere else as the season continued -- fans of the show have been trying to find out about Bob Benson. Much like the recent idea of Megan's death, the Benson character brought out many a conspiracy theory among fans of the show.

Is he a spy, a serial killer, a smoke monster?

Wolk said his favorite was the idea that Bob Benson was Pete and Peggy's baby, returned from the future.

Pete learned on Sunday's episode of Bob's past from Duck (his history was "written in steam," according to Duck), and considered what he might do with the newfound information. It was a scene reminiscent of the first season, where he attempted to bring down Don when he learned his story, only to have his efforts rebuffed by Bert Cooper.

The most likely theory was that Benson was perhaps a nouveau version of the show's equally mysterious protagonist Don Draper. Albeit, one with a more complex relationship with Pete, and one Pete could use to his advantage.

Wolk thinks that Bob sees differently, more than in a simply salacious way.

"I think Bob genuinely cares for Pete," Wolk told the magazine. "There are a lot of ways to care for someone. Sometimes it's love and sometimes it's just caring. Bob has a big heart in general - he's helped Pete (he found a caretaker for Pete's mother) and Joan (he accompanied her to the hospital when she had a medical emergency). He feels things and cares for people."

Wolk also described his admiration of other mysterious characters from movies, such as Ed Norton as Aaron Stampler in Primal Fear and Kevin Spacey as Keyser Söze in The Usual Suspects. He labeled them as "so much more interesting."

The actor was mysterious himself about the fate of his character in the upcoming season. He is due to star this fall on the CBS program The Crazy Ones with Robin Williams and Sarah Michelle Gellar.

"If Mad Men went on for 10 years, and if it were up to me, Bob would continue being mysterious," said Wolk. "I love characters that catch you off guard."

Check out this week's Inside Mad Men.

Watch the preview for Episode 13, In Care Of.

Tags: Mad Men