Neill Cameron’s opening to Tamsin and the Deep is attention grabbing in a manner setting the subsequent tone of tension. Annoyed that her slightly older brother won’t teach her to surf as instructed by their mother, Tamsin tries on her own. She ventures too far into the sea and is dragged down, briefly seeing a mermaid before losing consciousness. She awakens on a beach miles away, bedraggled and annoyed, clasping a driftwood stick, then has a long walk home where she discovers it’s been a month since she was last seen.

Over the coming days and nights Tamsin’s life is altered. Her brother is behaving oddly – well more oddly than usual for a teenage boy – she can hear birds speak and sees other strange creatures, and the driftwood stick turns out to be quite the talisman. Without realising it, Tamsin’s become involved in something ancient, evil and vengeful.

Cameron’s script is well balanced, offering light-hearted banter and a typical teenage brother/sister relationship where there’s a love, but it’s deeply buried beneath the daily irritations. Over the first half of the book he rations the fantasy elements, but when he trickles through some explanations it’s a story worth telling, in the gruesome fairy tale tradition where tragedy becomes matter of fact.

For all of Cameron’s skilful plot, it’s Kate Brown’s illustrations that bring Tamsin and the Deep to life. She employs a broad cartoon naturalism for everyday sequences, but it’s adaptable enough to cope when danger or horror is required, and, oddly, she switches to a more realistic style when Tamsin’s ancestry is related and the truth revealed. Where she’s not as good is in providing facial features. The big eyed exaggerated style is taken from manga graphic novels, but bolted on to her cartooning it leaves Tamsin with a pudgy ugliness. It’s partly the result of a plot element, but could nonetheless have been handled differently.

Tamsin’s an appealing personality, and Cameron has ensured that while her heart’s in the right place, she’s not too saintly for a modern day audience. He’s also provided a character revision for one of the greats of myth and legend that may not sit well with purists, but is imaginative and a possible nod to Neil Gaiman’s Sandman.

While intended as the opening volume of a series, which continues with Tamsin and the Dark, this is complete in itself. It is a book aimed at children, not a layered fable with universal appeal, but within those limitations thoroughly enjoyable for the intended audience.