Sheldon spent 45 days on his hobo train trip when his pants and belongings were stolen from a sleeper car. He contacts Leonard to come pick him up in Arizona. Leonard decides to bring Amy with him. She's upset that Sheldon called Leonard instead of her. Sheldon rushes to hug Leonard and then asks why Amy came too.  He goes over to her and instead of saying something nice to her, he says, "Shotgun."

Raj is getting his tinted windows removed because he now has a girlfriend to show off, so he drives with Howard. Wolowitz wants to stop by and check on his mom because Stuart moved out. Howard is glad Stuart's gone because he's uncomfortable with the relationship that's formed between Stuart and his mother. Raj suggests they are romantic and Howard freaks out. When Howard arrives at his mom's house, Stuart is still there and buddy buddy with his mom.

Howard freaks out about Stuart staying at his mother's house. Raj tries to convince him it's okay. Howard calls his mom and gets the answering machine with a joint message with Deb and Stuart. 

Penny has an interview for a job in pharmaceutical sales at Bernadette's company. She's nervous and tempted to cancel. Bernadette tells her to be herself and she'll do fine. In the interview, Penny says she's a people person and then explains how she sold food as a waitress. Penny blows the interview and asks the interviewer to not tell Bernadette. They end up bonding over how scary Bernadette is. Penny ends up getting the job.

Sheldon traveled all over the country, but never left any of the train stations. Amy is furious that Sheldon left without saying goodbye and then called Leonard for help. Sheldon confides in Leonard that he didn't call Amy because he didn't want her to know that he couldn't make it on his own. She tells him that it's okay that he's not perfect and that makes him want to break up with her.