"Be cool, Dad, we've decided to con Grandma." (Or, the one where the Stilinski men drag Derek to Thanksgiving dinner at Grandma's and she gets the right wrong idea.)

Alternate Title: "Dick Failwolf, Private Eye." (Or, Derek's hit with a Film Noir curse, which forces him to narrate his own life in luridly-detailed prose.)

Shortly after Arthur is resurrected in the 21st century, he finds Merlin's vibrator. That's it. That's the plot.