Hannah is a hotel worker, who struggles with depression after a trauma in her childhood and a toxic ex-boyfriend.

Callum is a student, questioning his own sanity since a strange young man appeared on the other side of his mirror.

When Hannah disappears, her brother Callum determines to find her. His journey leads him to Epping Forest and a mysterious waterfall. But Hannah has fallen through a portal to another world. Together with a Warrior called Fay, she must unveil the secret of the ancient prophecy before Therrhain is destroyed...

The Waterfall Warrior is a YA fantasy novel that also tackles normal day-to-day themes, such as discrimination and mental health. The central plot is that Hannah falls into another world which is both similar and very different to our own, and we experience this strange new place with her. At the same time, we also see the repercussions as Callum and the rest of her family do their best to cope with her disappearance.