Quick recap
After the second ceremony, the gang suspects Mary and Alfred spent the night together. The gyroscope becomes an Air Force project under Colonel Williams, and Leonard and Howard worry it'll become a weapon. Sheldon and Amy try living together in Penny's old apartment and decide to stay. Bernadette has baby Halley, and Howard learns to be a dad. Raj tries to get by without his parents' money, and Penny hosts her mother and brother. In the end, the military takes the gyroscope, and Amy spends the summer at Princeton. With her gone, Ramona Nowitzki hovers around Sheldon and kisses him. He flies to New Jersey and proposes to Amy the second she opens the door.
No spoilersOpens once you mark the title as seen.