An organillo is a little organ – a cross between a wind-up player piano and an accordion – that Stephen Mottram heard playing on the street in Mexico City. Whereas most of us would happily remember the strangely aquatic puffs and groans of the instrument as part of a holiday memory, Mottram came home and made one of his own, and uses its sounds as the inspiration for this, his latest show. The oddly arhythmical and melancholy sound of the organillo is woven into the electro-acoustic soundscape of this production in Sebastian Castagna's score, and provides a watery backdrop for the miniature narratives that Mottram's objects and puppets unfold. It is a shame that the sound of the organillo is not used more in the soundtrack – the electronic effects that replace it are not nearly so evocative as the instrument itself.

Mottram's creations are enchanting and at times disturbing. Exploring a theme of reproduction and transformation in a strangely amniotic sea, he conjures shoals of fish, finned humanoids with the distended eyes of aliens, strange creatures and a pair of disembodied hand puppets that are uncannily alive and incredibly expressive. As an exercise in constructing narrative through fragments and images, without any reliance on text or explanation, this production is really strong, although the denouement of the piece rather fails to live up to the time it took to get there. Some of the visual motifs are overused – there is only so much interest one can sustain in a shoal of fish – and the seductively hypnotic soundtrack only deepens the sense of sleepiness that this repetitiveness encourages. As a demonstration of Mottram's skills as an object maker and puppeteer, this show is wonderful, but as a piece of theatre it lacks the structure and development it needs to excel.