“Freedom, Part 1”/”Freedom, Part 2” – On a two-hour “Throwback Thursday” edition of “Grey’s Anatomy,” Meredith and Derek have one last shot at a successful outcome in their clinical trial as the other surgeons work together to free a boy from a hardening block of cement. Meanwhile, Izzie helps Alex care for an ailing Rebecca, and Lexie discovers critical information about George’s intern status on “Grey’s Anatomy,” THURSDAY, APRIL 14 (8:00-10:01 p.m. EDT), on ABC. (TV-14, S) (Rebroadcast. OAD 5/22/08)

These “Throwback Thursday” episodes of “Grey’s Anatomy” star 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, Chyler Leigh as Lexie Grey and Brooke Smith as Erica Hahn.

“Freedom, Part 1”/”Freedom, Part 2” were written by Shonda Rhimes and directed by Rob Corn.