Howard and Sheldon have had a successful trip to NASA in Houston, both getting along with the other. Their next stop is to visit Sheldon's mother, who he has not told he is coming. Sheldon ends up getting a bit of a surprise upon his arrival at his mother's house, a surprise which he wishes he didn't get. Sheldon has to figure out how he will deal with this surprise, both outwardly and internally. Meanwhile, back in Pasadena, Leonard, Penny, Raj, Amy and Bernadette are trying to figure out what to do for the evening when Stuart arrives unexpectedly. Within a few minutes, Stuart collapses on the ground and dies. Or at least he does in Raj's scenario of his murder-mystery night. The other four aren't too thrilled about Raj's unmentioned plan for their evening. As they progress through the game, a hypothetical in the game turns into a deeper discussion about their future.