Big Bang Theory (8pm, CBS) - The fifth season ends with Howard and Bernadette deciding to get married before his NASA mission, which causes the gang to scurry into overdrive to stage the wedding. NASA astronaut Mike Massimino has a cameo as himself.
The Vampire Diaries (8pm, CW) - The third season concludes with Elena wishing she could go back to simpler times when her parents were alive.
Community (8pm, NBC) - Abed develops a conspiracy theory and determines that Dean Pelton is an impostor. His search for the truth lands him in mandatory therapy sessions after he's caught sneaking around campus.
Grey's Anatomy (9pm, ABC) - The residents make their postresidency decisions. Also, Mark tells Derek that he's torn between Lexie and Julia, and Arizona encourages a childhood friend to have surgery.
The Secret Circle (9pm, CW) - In the Season 1 finale, Cassie and Diana tap into dark magic to help Faye fight off the Witch Hunters.
The Mentalist (10pm, CBS) - Jane receives a message from Red John on the eighth anniversary of the deaths of his wife and daughter.
Scandal (10pm, ABC) - As Gideon investigates Amanda's past, flashbacks recall the contentious primary race between Fitz and Sally Langston, who is now vice president. We also see how Olivia and Fitz first met on the campaign trail and how each of her associates joined her team.