In one of my recent reviews, I was bemoaning the lack of originality in low-budget British film making. The Library Suicides from director Euros Lyn is a near textbook example of how to do it correctly.

Twin sisters – Ana and Nan – discover their Mum’s body after an apparent suicide attempt. Her dying words, however, seem to implicate a man in her death. When that very man, Eben (Ryland Telfi) arrives at the library where the girls both work to research their mother with a view to writing her biography they hatch a plan to kill him and make it look like suicide.

Lyn manages to keep the tension building and the events just about believable (apart from maybe the ending, but more about that later) as the twists pile up on each other. Set almost entirely in the National Library of Wales, he uses that sprawling space really well. The cast is universally solid, with a good turn from Dyfan Dwfor, as the Dan the security guard, who provides the film’s most amusing moments.

The real star, though, is Catrin Stewart as the twins. I only know her from a not great performance in the Sky TV programme Stella, but here she is a revelation. At first the sisters seem identical, in character as well as looks, but she gradually and subtly unveils the difference between the artistic Ana and the colder Nan.

That final twist has left me puzzling. Jaw dropping at the time, but it really doesn’t stand up to much scrutiny. It was probably a step too far but it doesn’t stop this being an enjoyable watch.

Rating: 7.5 out of 10