"The Roommate Transmogrification" is the fourth season finale of the television series The Big Bang Theory that first aired on CBS on May 19, 2011.
However, when Bernadette announces that her dissertation has been accepted, earning her a Ph.D. and a well-paid job, Leonard seizes his chance and starts to mock Howard with the other guys, degrading him for being the only non-doctor in their group.
Raj likes the idea and moves in after Sheldon's usual bureaucratic procedures (including a modified "temporary roommate agreement" and a will).
At the end of the episode, Sheldon discovers Leonard sleeping on the couch at their apartment after his confrontation with Priya, just before Howard shows up after a fight with Bernadette over the watch.
[3] Carla Day from TV Fanatic gave the episode an extremely positive review by saying "I found the installment and each of the stories to be hilarious and/or to propel the characters forward.
Day did give the cliff-hanger a mixed review by writing "At first, I thought it was pretty funny, but now, I think it is just sad" and "I'm going to wait until the show returns and I can see how it all plays out before I decide if I like this new entanglement or not".