Amrapali Ambegaokar

Everyone in the hospital tries to find a new organ donor for a patient; Mark is left in a compromising position; Cristina tries to avoid Owen.

George's skill level dazzles the new interns; Meredith halfheartedly helps Lexie with her first emergency patient.

George and Izzie test their romantic chemistry; Derek asks for more than a physical connection with Meredith; Mark develops a crush on a fellow surgeon; Callie finds her role as chief resident jeopardized.

Cristina, back from her honeymoon trip, searches in vain for Burke; Meredith, Cristina, Izzie and Alex spend their first day as residents with their own groups of interns.

Addison, Naomi and Sam rush Archer to Seattle Grace, where they reunite with old friends in hope of saving his life; Izzie devises a medical game to teach the interns; Owen runs into someone significant from his past.

Teenagers fill the ER after a school-bus crash; Bailey treats a patient who was her high-school crush; Derek goes on a date with a fellow doctor; Thatcher enters the ER looking for Meredith.