Meredith and Derek get one last shot at success in their clinical trial; the surgeons work together to free a boy from a block of cement; Izzie helps Alex care for Rebecca; Lexie uncovers critical information about George's status as an intern.
Ritualistic murders lead the team to believe their suspect may have a fascination with the Salem witch trials; Garcia plans a Day of the Dead celebration.
After construction workers find an archbishop's body with the kneecaps surgically removed, the team returns to the case of the Widow's Son serial killer.
Melinda hunts down a ghost who is targeting young girls on a social networking website.