The premiere, which begins at 9 PM ET, is titled "Dream a Little Dream of Me" and is described as such: "Meredith and Derek learn that 'happily ever after' isn't easy, and a military doctor who brings in a trauma patient catches Cristina's eye."

Mariette Hartley and Kathy Baker also make appearances on the two-hour episode. Peters, Hartley and Baker play friends who all require care at Seattle Grace Hospital. The season premiere also sees the return of Jeffrey Dean Morgan as Denny Duquette.

"Grey's Anatomy" stars Ellen Pompeo as Meredith Grey, Patrick Dempsey as Derek Shepherd, Sandra Oh as Cristina Yang, Katherine Heigl as Isobel "Izzie" Stevens, Justin Chambers as Alex Karev, T.R. Knight as George O'Malley, Chandra Wilson as Miranda Bailey, James Pickens, Jr. as Richard Webber, Sara Ramirez as Callie Torres, Eric Dane as Mark Sloan and Chyler Leigh as Lexie Grey and Brooke Smith as Erica Hahn. Visit http://abc.go.com/primetime/greysanatomy for more information.

Peters was last on Broadway in the acclaimed revival of Gypsy, for which she received a 2003 Tony Award nomination for her performance as Rose in the Sam Mendes-directed production. She won her two Tonys for her performances in Andrew Lloyd Webber's Song & Dance and Irving Berlin's Annie Get Your Gun, and she has also starred on Broadway in Mack & Mabel, On the Town, Sunday in the Park with George, The Goodbye Girl and the original production of Stephen Sondheim's Into the Woods. Peters' newest live recording, "Sondheim, Etc., Etc.—Bernadette Peters Live at Carnegie Hall (The Rest of It)," is available on the Angel Records label. Masterworks Broadway has also released a "Legends of Broadway" CD celebrating her theatrical career. Peters' screen credits are numerous.

The actress is also the author of the best-selling children's book "Broadway Barks," which benefits the charity of the same name.