Helen Slater

A young boy needs a heart transplant but doesn't seem to want it, and his treatment causes Burke and Yang to have philosophical differences. Meanwhile, when the interns rally to help Alex prepare to re-take his exam, Meredith has to remind Izzie of the true spirit of the Christmas holiday; and despite a reconciliation with his wife, Derek isn't in a festive mood.

The body of a 16-year-old girl is found while Benson (Mariska Hargitay) and Stabler (Christopher Meloni) are chasing down a rape suspect. The victim is Shannon Coyle (Jenna Gavigan) and her grief-stricken mother Susan (Helen Slater) and brother Brian (Spencer Treat Clark) are devastated. She was at choir practice and never made it home. The detectives were having some difficulty with leads and when the choir teacher's prints come up (on a secret key in Shannon's purse), they think he is the suspect. They go to his apartment and find him in bed with Shannon's best friend, Lisa (Stefanie Nava).

Rather than be apart on Thanksgiving Day, Will (Eric McCormack) and Grace (Debra Messing) join Jack (Sean Hayes) and Karen (Megan Mullally) for a festive holiday motor tour of their respective dysfunctional families, including Grace's domineering mother (guest star Debbie Reynolds) as well as Will's willful mom (guest star Blythe Danner, "Meet the Parents") and Jack's step-dad (guest star Beau Bridges) - with unsettling results. Meanwhile, back home, a waiting Rosario (Shelley Morrison) bastes and tastes their juicy turkey. Helen Slater ("City Slickers"), Jon Tenney ("Brooklyn South"), Lainie Kazan ("The Nanny") and Kenneth Mars ("The Producers") also guest star as other bizarre family members. Part 2 of 2.

Cooper and Charlotte try to forgive each other after revealing secrets in couples therapy.

Clark hears his mother's voice trapped in Kara's crystal, and releases her. She gives him Jor-El's ring made of Blue Kryptonite, which strips him of his powers.