Heathers is a darkly sardonic look at life in an American high school, based on the 1989 film. It’s rude and crude and probably not suitable for children wanting an introduction to the modern musical but it has a thread of sanity, mostly in its no- nonsense narrator, Veronica Sawyer (Belle Nicol). Veronica doesn’t want to be a target at school so she attaches herself to the in-group, the Heathers.

The Heathers are three girls who make the rules but they let Veronica in because she has talents as a forger of school documentation and passes and notes in others’ handwriting. One of these is left with devastating effect for the forlorn Martha (Chelsea Heaney) who is definitely not among the chosen when it comes to relationships and cool.

How this all unfolds has echoes of Monty Python crashing into an American St Trinian's with a touch of The Book of Mormon and a dash of South Park. Veronica falls for new boy J.D. (Will Huang) who is not like the jocks and nerds but something almost more dangerous, a thinker and reader.

There are deaths and ghosts and attempted suicide and voices from beyond the grave. There’s teenage grossness and teacher nerdiness all done with great energy by the cast. The Heathers triple act (Charlotte Gearside, Madeleine Betts and Mikayla Brady) is ghastly in its controlling behaviours and the three performers are full of the right precision and caricature.

Heaney does a grand double act as both the gentle Martha and teacher Pauline Fleming, who is a little grotesque in her attempts to aid the students by some kind of group therapy. There’s another forceful double act in the unpleasant pair of entitled boys, Ram (Pippin Carroll) and Kurt (Pierce Jackson).

But it’s Huang’s dark and desperate J.D. and, more so, Nicol as narrator Veronica who lead the show down some dark alleys to some kind of coming to terms with youthful human behaviour.

The set and lighting are a little basic but the mutiple use of school locker doors is imaginative and the double movable staircases add variety. Choreographer Nathan Rutups finds plenty of work for the cast as they recreate teenage dance. Musical director Matthew Webster pushes the show along admirably and the singing is mostly clear and full of the proper kind of energy.

Heathers will not be to everyone’s taste but for those who like a little vinegar (or should that be drain cleaner?) in their musicals it will go down well.