The dark touch of bestselling author Philip Pullman is unmistakable. The man who famously depicted the death of God in the award-winning His Dark Materials trilogy is also the author of Clockwork, a novel forming the basis for a touring children’s opera, performed by Unicorn theatre company.

It tells the story of Karl, a clockmaker’s apprentice, who has failed to produce the clockwork figurine that should mark the end of his apprenticeship. While Karl drowns his sorrows, a storyteller recounts the tale of Dr Kalmenius, a mechanical genius believed to be in league with the Devil.

As the storyteller speaks, a man matching his descriptions enters the tavern and introduces himself as Dr Kalmenius and offers to help Karl.

Clockwork snakes its way through intertwined plot twists. All children’s theatre should be this good and all writers as skilled as Pullman.

But the production is let down by the medium. There are no arias or memorable themes to justify operatic treatment. It fails to observe the cardinal rule of musical theatre, that songs must also advance the plot.

This diminishes the edge-of-seat tension that Pullman’s masterful storytelling deserves: a musical spanner in otherwise faultless clockwork.

www.unicorntheatre.com