Magic is real. But so are monsters. Oisin dreams of being a hero, like the ones he reads about in books.

So when he overhears a plot for a midnight raid on a Dublin museum, he knows this is his chance. But Oisin soon realises that heroes must fight monsters. Dark things that lurk in the shadows – like the sinister Fomorians – don’t take kindly to those who get in their way.

With the help of legendary troublemaker Fionn Mac Cumhaill, can Oisin prevent death and destruction? Or will modern Dublin find itself at the mercy of the mythical monsters it had forgotten?