When Alan becomes a little too lonely and becomes obsessed with building model cars, Chelsea decides to set Alan up on a blind date with one of her friends.  Chelsea, Charlie and Alan go to meet her for the double date.. and it turns out it's Rose.  So that Chelsea will never find out his crazy history with Rose, they all pretend like they've never met for one of the most hilarious dinner scenes ever.  We find out that Chelsea and Rose met because Rose followed Chelsea everywhere she went in typical stalking Rose fashion.

Alan and Rose end up hitting it off and sleep together that night.  Rose becomes a crazy stalker and follows Alan as he goes to the movies with Jake.  Alan tries to tell Rose he needs space, and she does not like the new confident side of Alan.  He ends up waking up with one of his model cars glued to his crotch.