Ah, the tender moment of reunion between parent and child.

Have you ever wondered who the parents of PCs in your game are? Your players probably never have either. Try introducing them at some point. They could be rural homebodies, whose progeny has made good by going out into the wide world to seek fortune. Or they could be adventurers themselves, approaching retirement, but still keeping a hand in with the orc-slaying business.

Or they could be the bad guys. Yes, it's been done. But that just means your players wouldn't dare suspect you of pulling this twist.

Transcript

Leia: Please! If you are truly my father you cannot destroy Naboo!
Darth Vader: You do not know what ills this planet has visited upon our family, my child.
Tàrkin: Mah Lord Vader, surely you see ze entire raison d'être of ze Peace Moon will be utterly defahled bah zis act!
Leia: Listen to him!
Darth Vader: Do not cry, daughter. Naboo has carried its mortal wound long enough.
Darth Vader: Crippled from the depredations of the Trade Federation. Reborn, but imperfectly.
Darth Vader: This world holds great pain. A terrible, unforgivable crime. Its memory burns through the Galaxy, a searing indictment of our past.
Darth Vader: You and I are united by this tragedy. Weep not, for our sins shall be erased.
{beat}
Tàrkin: You are one sick croque-monsieur.