Overview: This season the Big Bang gang’s romantic universe expands. On the rebound from Penny, Leonard falls into the arms of Raj’s sister Priya. Sheldon gets a girlfriend, or rather a friend who is a girl: Amy, a dour neurobiologist who declares herself besties with Penny. Howard and Bernadette heat up. And so do Raj and Bernadette (at least in Raj’s Bollywood daydream). All in the furtherance of award-winning genius comedy.

DVD Verdict: The fourth season, like all the other seasons, is completely brilliant. This was the season when the girls team really came into its own - Amy Farrah Fowler and Bernadette are a splendid addition to the proceedings. The Priya character, unfortunately, is not in the same league - partly because she has a thankless role, but also because the woman playing her hasn't got the comic energy of the other women (hardly anyone does!) and looks dull beside them. But the others are a gift.

The only very, very bad thing about this season is the unbelievably terrible decision at the very end of the last programme to hook up Penny and Raj, a series wrecking decision if there ever was one. The fivesome only worked when, at bottom, there was a common sense of trust among them (their essential innocence). This wrecks it. The secret truth of TBBT is that the whole thing is kept together by Penny, whose love for the guys makes us believe that they wouldn't do truly bad things, and that the crude things they do or often say wouldn't creep us out.

She's their sister in some sense (we know that their bawdiness with her is not a serious threat to her relationship with Leonard). This stupid move wrecks that. (Fans can check out the tensions brought out by a more minor betrayal in 'The Irish Pub Formulation". That could be redeemed by a certain amount of mutual humour, but we are dealing with something more serious - internal to the fivesome - here.)

I don't see how the show can ever recover from the betrayals involved. Stupid, stupid, stupid. The writers are very smart, but this seems unrecoverable, no matter what they do. It raises the question whether the writers have lost the conception of the thing in the need to do new and exciting plot devices (in spite of the statements by the Executive Producers that the Big Bang Theory is all about character). This is a Widescreen Presentation (1.77:1) enhanced for 16x9 TVs and comes with the Special Features of:

Actor on Actor: The Big Bang's Theory of Relativity Featurette
Barenaked Ladies on Big Bang Theory Featurette
'History of Everything' Music Video
Gag Reel