1 Series, 4 Episodes
The guys work around the clock on the Air Force project, leaving Sheldon fighting to stay awake. Penny and Amy attend a university gathering. Raj learns Bernadette's true feelings about her pregnancy.
Howard has a meeting with Air Force representative Colonel Williams about the gyroscope he invented with Leonard and Sheldon. Penny carelessly reveals Bernadette is pregnant to her colleagues at work.
The group of friends face an awkward morning after Sheldon's mother and Leonard's father share an evening together. Penny's family arrive in town to attend Penny and Leonard's second wedding ceremony.