The Big Bang Theory

The writers never get tired of the bringing together of opposites. And why would they, when it works every time? In the penultimate episode of the series, Sheldon and Leonard’s mothers – one a drawling creationist, the other a purse-lipped psychiatrist. It’s like a summit of superpowers: we know there will be fireworks, the fun is anticipating what will light the touchpaper.

The meeting raises at least two questions: why is Beverly so ghastly to Leonard, and how could Mary possibly have given birth to Sheldon? Those answers may prove elusive, but the story does end with a very surprising hug. Laurie Metcalf is hilarious as Mary; we don’t see nearly enough of her.

There is a sub-plot about Raj, Howard and Stuart being slobby, but that’s a bit like the third bout on a fight night, when most people have gone home.