"Oh, for Christ's sake, this is interminable" says Tennant at one point in this follow up to the 2007 effort. You're not wrong boyo. That said, this scattershot affair, though overlong, does everything it can to keep the viewer engaged with fast cutting, obvious gags and overripe performances. Not least that of Everett as the Camilla Parker-Bowlesish head mistress Miss Fritton passing out sage advice to her girls.
Tennant plays the arch villain, the suavely nasty Sir Pompey out to retrieve a ring that is buried in the school library. This 420-year-old object is apparently the key to limitless treasure but the school has only half the ring. The anarchic students then go on a mission to seek out the other half before Tennant's dastardly mob can find it. The girls pretend to be be males at a boys school in order to locate it, stage a flash mob at Liverpool Street station to evade their detractors and end up at Shakespeare's Globe theatre on London's South Bank where the treasure can be uncovered. Though it's not what they're prepared for. They're aided by the love of Fritton's life, Geoffrey Thwaites (Firth), a booze-soaked. washed up has-been now with a shot at redemption. And Kelly (Arterton), the former head girl of St Trinian's, now working as a secret agent, is also roped in to help with their assignment. The various sub-groups of the school - posh totty, chavs, emos, geeks etc - are back working in harmony again.
Harding plays another student, a rock chick predictably enough, though she looks a good decade older than any of her counterparts. Riley is the head girl this time and in one scene is possessed by a demon (don't ask) so this scrappy effort can take the mick out of The Exorcist. The Lord Of The Rings comes in for ribbing too. It's on a par wth the first movie - throw everything at the wall and see what sticks - though there's no Russell Brand this time round. But it's all done with larky, high-spirited gusto. If one joke fails, which it invariably does, another one will be along soon after. Kids should enjoy it, though it's only fitfully amusing for adults. Agreeable enough if you're completely undemanding, wearisome and trying if you have more elevated expectations.