Only a Monster
Sixteen-year-old Joan Chang-Hunt is sent to stay with her late mother's eccentric family in London for the summer. She loves her job at the historic Holland House, and when her co-worker Nick asks her out, life seems to be falling into place — until she learns the truth: her family are monsters, one of twelve secret monster families hiding in London, able to steal time from humans. Nick, it turns out, is a legendary monster slayer sworn to destroy them.
When a devastating attack forces Joan to travel back in time, she must team up with Aaron Oliver, the ruthless heir to a rival monster family, to save the people she loves — and decide who she is willing to become to do it. The first book in Vanessa Len's Only a Monster trilogy, an urban fantasy that asks what happens when the girl at the centre of the story isn't the hero.
Half-monster, half-human teenager who discovers her mother's family are monsters able to steal time from humans.
Joan's coworker and crush, revealed to be a legendary monster slayer bent on destroying her family.
Only a Monster was a finalist for the 2022 Aurealis Award for Best Young Adult Novel (Australia's speculative fiction awards). Sources on whether it went on to win the category disagree, so that stronger claim isn't recorded here.
Yes — it's book one of Vanessa Len's Only a Monster trilogy, followed by Never a Hero (2023) and Once a Villain (2025).