Returns: Thursday, April 24, at 9 pm/ET (ABC) Number of new episodes: 5

Where we left off: Derek decided to build his McDream house, but Meredith faltered in sharing it with him, especially after George inadvertently revealed that Derek made out with nurse Rose. Izzie and George were in romantic limbo after their affair broke up his marriage. Mer's half sister, Lexie, was hooking up on and off with Alex, who'd also been hooking up with his former patient Ava (Elizabeth Reaser). After a nearly tragic accident involving her son and a bookcase, Bailey blamed her husband, who is now moving out. What's next: "We'll have leapt ahead five or six weeks in time," creator Shonda Rhimes says. " But it'll be very clear from the first moment what has transpired. You'll see where things stand with Derek and Meredith and Rose. You'll see where George is living, and in the first episode all the residents will be involved in a high-stakes surgical contest - definitely not something the chief would condone." The Mer-Der chronicles: "I am pretty dedicated to the idea that they are to be together for good this season," Rhimes says. "What's going to be interesting is how she gets her act together, and how they decide that this is it." Are those wedding bells we hear?! "I did not say there is going to be a wedding," Rhimes says. "Or a ring. Although I did not say there wasn't going to be a ring." Flamethrower: Addison (Kate Walsh) will pop up at Seattle Grace to perform surgeries that only she can do and "discover whether you can ever really go home," Rhimes says. For more Grey's preview, pick up TV Guide's Returning Favorites issue. Watch full episodes | Photos | More Returning Favorites coverage