The Intimacy Acceleration
'The Intimacy Acceleration' - Season 8, Episode 16
Sheldon and Penny spend the evening performing an experiment to see whether people can fall in love in a few hours. Meanwhile, Leonard, Amy, Raj and Emily visit an "escape room" where they are tormented by a zombie. Meanwhile, Howard and Bernadette encounter trouble as they fly back from Mrs. Wolowitz's funeral.
Air Date: February 26, 2015.