"I Saw Her Standing There" - Aware that Derek might never operate again, Meredith stops talking about the surgeries she's performing. Meanwhile, Richard calls on Dr. Catherine Avery to help him perform a complicated procedure, as things continue to heat up between Jackson and April; and Arizona's struggle to accept her fate forces Callie and Alex to face their guilt, on "Grey's Anatomy," THURSDAY, OCTOBER 25 (9:00-10:02 p.m., ET) on ABC.