Grey's Anatomy Grey's Anatomy

Inside Meredith and Derek's bedroom on the Grey's Anatomy set, a very naughty Patrick Dempsey climbs on top of his costar and friend of six-plus years, Ellen Pompeo, and admonishes there is to be "no thrusting." Joking that he's been "doing steroids" over his summer break, the pumped-up star plants one on Pompeo's lips before making an accusation that catches his leading lady off guard: "Did you just have a jelly doughnut?"

The lighthearted high jinks are welcome on a set that has been plagued with discontent for far too long. "I'm glad for the other folks who have gone on to do things that make them happy," says costar Sara Ramirez (Callie), referring to the departures of Isaiah Washington, T.R. Knight and Katherine Heigl. "But the people who are here now are here because they want to be."

And it shows. "We were a family in crisis," says creator Shonda Rhimes. "I had a conversation with the cast [saying] it feels like we went through a war together and we've all come out the other side. Now it feels like we're sitting on the porch watching the kids play."

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Perhaps no two are more deserving of a playdate than Dempsey and Pompeo. In May's shocking season finale, a crazed gunman shot Derek in the chest, and the trauma led to the miscarriage of the child Meredith had only just learned she was expecting. Season 7 picks up a couple of months later, with Derek healed physically, but not emotionally, and still unaware of Meredith's ordeal. Acting out, he misses Cristina and Owen's candlelight wedding when he's locked in the slammer for reckless driving. This prompts Meredith (in Episode 2) to reveal her miscarriage to Derek, with the plea that he curtail his speeding before he, too, is taken from her. "It's really quite beautiful," says Rhimes.

And it seems the loss will inspire them to try again. Earlier on set, Dempsey and Pompeo shot a consultation scene with a fertility doctor, who will inform Meredith that it was more than stress that caused her miscarriage. Turns out Dr. Grey has something called a "hostile uterus" (not to be confused with the "incompetent cervix" Meredith fears she may also have).

"Meredith has a really good sense of humor about this," says Rhimes. Not surprisingly, so does Dempsey, who entertained Pompeo in between takes by removing a plastic fetus from its embryonic casing and playing with it like a doll.

"Patrick and I are both from New England, so I think we're both particularly salty," says Pompeo, who later suggests crying during a sex scene as an antidote to her costar's ribaldry. "I'm sure some people find it annoying, but it's all in fun."

But fun and games take a backseat to the respect they share for the integrity of their characters, and both acknowledge the baby-making story line has caused them some confusion.

"I was shocked," says Dempsey. "For the longest time Shonda said, 'Meredith's not having any kids.' I was convinced that wasn't going to be an issue for us to play." Besides, adds Pompeo, "This show is difficult enough to shoot without the added element of a baby."

Rhimes offers up this explanation: "There's nothing like almost losing the man you love and finding out you're pregnant and losing the baby on the same day to make you realize what's really important." Dempsey — himself a father of three — is now on board with the story line: "I'm excited to take this next step. If they don't have a child now, I don't think they'll survive as a couple."

But even before their next pregnancy test turns positive, Mer and Der have already evolved into the old married couple Rhimes vowed they'd become after fans (and the actors) grumbled over the couple's constant breakups and makeups. Case in point: For her bedroom scene, Pompeo's not in a sexy nightie, but in grey sweatpants and a shapeless Dartmouth jersey.

"If I'd worn this myself, I never would have had a baby," kids the real-life mom to 1-year-old daughter Stella Luna. "The look is fundamental to who Meredith is, but it's just not particularly conducive to baby-making."

Frumpy attire should be the least of Meredith's concerns this season. Fearing she may pass on the genes of her Alzheimer's-stricken mother, not to mention alcoholic father, she tells Derek he'll wind up one day babysitting "a drooling 80-year-old wife with a drooling 50-year-old child." This drives Derek to team with Cristina (Sandra Oh) to find a cure for the disease.

"Sandra and I are working together in a way we haven't seen before," says Dempsey. "We're very intertwined. The shooting tragedy affected Cristina on a very deep level, so she and I have an experience together that no one else shares."

For more with the Grey's Anatomy stars, pick up a copy of this week's TV Guide Magazine, on newsstands Thursday, Sept. 23!

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