Kai Lennox

Derek and Addison's disagreements become professional when their close friends have a medical crisis; Cristina and Burke try to have a normal date but it does not got as planned.

Brennan and Booth travel to Mexico to investigate human remains with extraterrestrial attributes; Angela and intern Wendell come clean about their relationship.

The team investigate the death of a petty officer. They soon discover that he may have been leading a violent, secret life.

Castle is abducted and subjected to a humiliating series of mind games and puzzles; Beckett and the precinct work desperately to recover Castle and unveil a murderer.

When a homeless teenager's (Bridgit Mendler) symptoms get worse, adult consent is required for an invasive surgery; Taub tries to connect with his daughters; House threatens Foreman's relationship with a married woman (Yaya DaCosta).

Michael and Sam continue the hunt for Maxi's killer; Jesse, Fiona and Michael help a scientist recover a revolutionary formula from his greedy and duplicitous former business partner.