The guys make plans to celebrate Star Wars Day on May 4th.

Arthur Jeffries dies and Sheldon deals with the death in his own way. He skips the funeral to celebrate Star Wars Day. He takes a nap and has a dream that Arthur is his Obi-Wan.

Penny and Leonard attend the funeral. They end up discussing regrets, which leads to Penny asking Leonard to marry him as a joke. He won't give her answer. 

Bernadette and Amy make a Death Star Cake.