Penny receives an unwanted visitor from Nebraska named Christy. In Penny's eyes, Christy is a loose woman with no morals. Hence, Christy is ripe for the picking by Howard. As Howard and Christy have a spontaneous get together using Penny's bedroom, Penny decides to ask Leonard and Sheldon if she can sleep overnight at their place, which elicits different responses from Leonard and Sheldon. Beyond Penny's sleeping problem, Howard hooking up with Christy causes more issues. First, Leonard, Sheldon and Raj are now missing a fourth in their regular activities. And second, they can all see that Christy is only using Howard. They have to figure out how to get Howard back.