A.J. Langer of My So-Called Life fame will be coming to Private Practice in a recurring role this fall, debuting in the fourth episode of the coming season on ABC.

She will be playing “someone from an Oceanside doctor’s past.”

Whoever that person is, her arrival will shake things up. Private Practice star Kate Walsh told TV Line's Matt Mitovich that: “A good little bomb gets dropped.”

As for who that bomb is dropped on, speculation is that Cooper and Charlotte may be in for another bump in the road after enduring a traumatic Season Four.

“I cannot confirm or deny those rumors,” Paul Adelstein said, while conceding, “Something’s coming down the pike, and it’s a big bump in their relationship."

“I don’t know if it’ll threaten [Cooper's marriage], but it will be certainly something that would be hard for any couple to adjust to,” he said of the "bump."

KaDee Strickland, Paul's on-screen partner, wouldn't reveal much more, saying: “I can tell you that A.J. is playing a really key role on this show, and a really interesting role on this show, and I’m excited about her role on the show.”

Don't assume the worst for Cooplotte, either.

“People really root for Charlotte and Cooper, and I think Charlotte and Cooper are doing a really good job of making the relationship work,” Adelstein said.

“I think people will be happy with what they’re doing [in Season 5].”

Who do you think Langer will be playing? What sort of developments do you predict for Cooper and Charlotte, and on Private Practice in general? Discuss!

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.