Leonard is devastated by the new friendly relation developing between his mother and Penny. Meanwhile Sheldon takes a detour with Raj and Howard to explore the old belongings of Howard's Science Models.
The guys are stranded in the middle of nowhere when Leonard's car is stolen on the way to the Bakersfield Comic-Con. Back home, the girls try to figure out why the guys are so fascinated with comic books.
Sheldon gets Alex to buy a Valentine's Day gift for Amy. Leonard and Penny and Howard and Bernadette have a disastrous dinner together. Raj and Stuart host a "Lonely People" party at the comic book store.
A date between Raj and Lucy takes both of them out of their comfort zones. After a trip to Las Vegas goes awry, the girls join in on a Dungeons and Dragons game, which causes Amy and Sheldon to re-evaluate their relationship.