This fantasy novel is the story of young Jack who was born on the coldest night of the year, so cold that his heart is frozen. To save his life, the midwife, Dr. Madeleine, who is also a mechanical genius and suspected witch, grafts on a cuckoo clock to act as his heart. The clock dismays would-be adoptive parents, so the orphaned Jack continues to live with Dr. Madeleine and her entourage in 1800's Edinburgh. Dr. Madeleine warns him that strong emotions may damage his fragile heart; above all, he must not fall in love.

But of course he does. On his tenth birthday he encounters Miss Acacia, a street singer with a glorious voice and poor vision. Despite her propensity for bumping into things, she too recognises the connection between them. However, the two children are separated, and the novel becomes Jack's quest to find Miss Acacia again. This quest sends him to school, over Dr. Madeleine's misgivings, where he encounters a bully who takes delight in torturing the small boy. Eventually he sets out across Europe for Andalusia where he believes Miss Acacia to be living. Along the way he encounters Méliès, a magician and clock-tender, who joins Jack. In Andalusia, he finds her performing at the Extraordinarium, a sort of ongoing carnival.

With such a whimsical start I had high hopes for this novel. I listened to the audio version, read by Jim Dale, my favorite reader, with his evocative voice and strong characterisations, so the book had everything going for it. However, I became bored rather quickly by the focus on Jack and his increasingly unattractive emotions. As his behavior deteriorated, I became fed up with him and wished for some other storylines. Malzieu has wonderfully inventive side characters, including Madeleine and Méliès, two prostitutes and a man who have also been the recipients of Madeleine's wizardry—Arthur plays When the Saints on his metallic spine—and the brusque owner of the Extraordinarium. I wish the author had made more use of these side characters, both for their intrinsic interest and to give some relief from Jack's complaints.

First published in French as La Mécanique du cœur (The Mechanic of the Heart), it has also seen light as an illustrated novel and a concept album, La Mécanique du cœur, by the French rock band, Dionysos—Mathias Malzieu is their lead singer—and is soon to be released as an animated feature film. Although it sounds as though it should be appropriate for YA or adults, the rather obvious sexual imagery makes it more of an adult fairy tale.

There are some lovely images and ingenious descriptions, as well as of course the marvelous core image of the clock-heart, but I found the book disappointing. Aside from my increasing dislike for Jack, the love story that propels the plot never seemed real to me, perhaps because Miss Acacia, described in Jack's first-person narration, is never presented as more than a pretty picture; we don't learn anything about her as a person. Although it may seem odd to say about what is, after all, a fairy tale, the ending seemed far-fetched to me—even in fantasies, I look for internal consistency—and somewhat clumsy. Yet the material is so promising! Perhaps it is better served by its incarnation as an album or illustrated novel. I will also look for the film, which is due to be released in October, 2013.