With echoes of Cornish folk tales, Jethro Compton Presents Sirenia is an eerie production, which cleverly uses its unusual venue to transport the tiny audience to a lonely lighthouse in the sea. As ever with Jethro Compton’s shows, this is an unusual and impressively put-together play – even if it’s not faultless.

From the outset, when a voice on the radio reports the failed search for a missing lighthouse keeper, there’s a tense atmosphere which only builds as the mysterious story unfolds. The missing man, Isaac Dyer, enters the room as the play goes back to the events leading up to his disappearance. Ominously, he’s warned on the radio that there’s a large storm coming; the audience quickly learns that Isaac’s physical isolation reflects his own vulnerability. As the storm rages, he is compelled to confront his past when he rescues a woman from the rocks.

I was gripped by the story as it unfolded, particularly as Isaac is forced into making an agonising decision and slowly begins to reveal his sad history. Meanwhile, true to past form, the set was particularly spectacular – filled with wonderful details designed to take the audience well away from the bustling heart of Edinburgh. The interior of the room reflects Isaac’s struggles; the three-quarters-empty bottles of rum lying casually in the background hint at someone who’s trying to escape his past. The use of light, too, has a genuinely dramatic effect.

But when Sirenia takes a sinister turn, the characters become something of a cliché, a fact which detracts from the overall sombre tone of the production. For me, this made the second half weaker than the first; I was frustrated that such a carefully-staged production was marred by such a fundamental aspect of its storyline.

So the writing isn’t as strong as other aspects of the play, but Sirenia is certainly moving, and has an interesting premise.  It may be set against the dramatic backdrop of the Cornish coastline, but Poldark this isn’t; it’s a mournful, atmospheric piece, defined above all else by the striking and immersive space it's performed in.