Kate Walsh and Benjamin Bratt, Private Practice Kate Walsh and Benjamin Bratt, Private Practice

What's the one thing Private Practice's Addison Forbes Montgomery wants more than anything else in the world?

A baby, of course! Over the course of the series, Addison (Kate Walsh) has struggled with her inability to have a child, as well as Sam's refusal to start a new family with her. Benjamin Bratt to the rescue!

Private Practice finale scoop: Who is Addison's new mystery man?

He's no babydaddy, but in the season premiere of Private Practice, we'll learn how Bratt's character, Jake Reilly, will help Addison. "It turns out he's a fertility doctor," Bratt tells TVGuide.com. "And not just a fertility doctor, but someone who is quite accomplished and up to speed with cutting-edge technology and procedures."

Addison actually met Jake in last season's finale, when he invited her on a spontaneous Fijian getaway. She turned him down and instead returned to Sam (Taye Diggs), so her reunion with Jake will be tense. "She's a little freaked-out and shocked," Walsh says. "Awkward, awkward, awkward. But also, it's totally intriguing for many reasons. It's something that she, no pun intended, thought that she put to bed and he's back. It just so happens he's got something that she really wants."

Will Private Practice's Pete survive?

"As their relationship evolves over the season, it'll be complicated in a good way, because what we've already discovered about them is that there's a very strong, undeniable physical attraction " Bratt adds. "With her renewed commitment to Sam, and revealing who he is and what he does, and how that brings him into their sphere, things have to be kept secret."

Funnily enough, Jake and Sam will meet independent of their relationships with Addison. "They actually hit it off," Bratt says. Eventually they'll figure out the woman they have in common. "When that gets revealed, it's pretty fun to watch."

 Private Practice returns Thursday, Sept. 29 at 10/9c.