The audience are not only on their feet but onstage inspecting the giant cabinet that dominates this collaboration between Candice Edmunds and Jamie Harrison's Vox Motus company, playwright Peter Arnott and the Royal Lyceum.

The conceit is a piece of Victorian hokum in which the two Davenports of the title, Ira and Willie, conjure up spirits from within their cabinet under the half-lit scrutiny of a scientific spiritualist society. Introduced by the grandiloquent Mr Fay under the watchful eye of the desperately seeking Lady Noyes-Woodhull, Willie, the younger of the two, is apparently possessed by his dead sister Katie as his spirit guide in a seance. When Willie goes off message, truth becomes stranger than ghost stories.

As the spirit cabinet opens up, this reimagining of the real-life story of the Davenports lays bare the roots of their act in a damaged, bare-floorboards childhood, in which a mother hallucinates heaven while a brutal father abuses Katie to death. The psycho-sexual scars are plain to see, particularly in Willie, played by a whey-faced Scott Fletcher opposite his brother Ryan as a more practical, if perplexed, Ira.

The first half-hour's box of vaudevillian tricks are a curtain-raiser to what follows in a big, technically complex piece of Freudian expressionism, the essence of which is about blind faith, hope and the power of suggestion. Accompanied by Phamie Gow and Jed Milroy's live piano and fiddle score, Vox Motus have created a spine-tinglingly serious treatise on what the imagination might be capable of if we only let our demons out.

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