The Evil Corp hack is threatened by a mystery man from Elliot's past.
Tensions rise when Sherlock and Watson are teamed up with Lestrade to find the person responsible for a bombing.
Frasier's old love, Diane Chambers, comes to Seattle for the grand opening of her play about the "losers" at Cheers and their hopeless obsession with "Mary Anne."
In a psychiatrist's office, Frasier and Niles each recount their disastrous attempt to go into practice together.
Al proudly announces he's saved up $280 in his Christmas Club account for presents, but his hard work is put in jeopardy when he is unable to get to the bank before it closes on Christmas Eve. Meanwhile, Steve leaves Marcy to spend Christmas with his mother in Cincinnati.moreless