Leonard's dad makes his debut in The Big Bang Theory ' s Season 9 finale Thursday, and his appearance sets off a series of events that could disrupt the natural order of the entire geek squad. Catch up on all this week's Mega Buzz Dr. Alfred Hofstadter (TV veteran Judd Hirsch ) comes to witness Leonard and Penny's re-do of their wedding vows, and while it's Leonard's big day, his dad might be the one who ends up getting lucky... with Sheldon's mom! At first, loathing Leonard's mom Beverly ( Christine Baranski ) seems to be all Leonard's psychiatrist dad and Sheldon's religious mom Mary ( Laurie Metcalf) have in common. But by the time the gang gathers for the reception dinner, Mary and Alfred are thick as thieves, and skulk off together for a nightcap. [Insert live-audience "woo" sound here.] Crave scoop on your favorite TV shows? E-mail questions to mega_scoop@tvguide.com or drop us a line at Twitter.com/TVGuide .
