The universe of Leonard & Sheldon is endlessly complicated and hilarious as THE BIG BANG THEORY enters the tenth dimension! Last season, Leonard and Penny went from next-door neighbors to next-door newlyweds. This season, they'll do it again with family. Meanwhile, Amy & Sheldon contemplate a coitus clause; Howard & Bernadette prepare for a little Wolowitz: and Raj juggles two girlfriends!