As Jack begins to build a relationship with his biological father, Milton’s (Alan Alda) health hangs in the balance. Despite Liz’s relationship track record, she draws public attention as a relationship expert after a talk show appearance. Meanwhile, Tracy’s high school invites him to speak at graduation and Kenneth must help him overcome embarrassing memories from his high school experience. Also appearing in the season finale are Clay Aiken, Mary J. Blige(!), Elvis Costello, Sheryl Crow and Adam Levine(!)

Hmmm... don't know how all these guest stars will fit in the episode.
Will Jack give his dad(?) his kidney?

WATCH TONIGHT!