The Ward Witch by Sarah Painter

Mysterious, magical, and a little bit deadly... Welcome to Unholy Island.
Esme Gray runs the guest house and tends to the ethereal wards that protect the island. She's sheltering from a terrible past and will do anything to stay safely hidden.
Luke Taylor has been searching for his missing twin for months, but has begun to believe that his brother might be dead. With his hope in tatters, a tip off leads him to a remote tidal island in the North Sea. It's further out than the famous Holy Island, and far stranger.
Visitors shouldn't be able to stay for more than two nights, so when Luke breaks this rule, the close-knit community is sent into turmoil. The residents of Unholy Island have secrets and they intend to keep them.
When Luke stumbles across one of the islanders dead on the shore, he finds himself under suspicion, made worse by his own troubles washing up on the tide.
Esme is drawn to Luke, but she doesn't trust her own instincts. That's not ideal for a witch, and especially not when there is a killer on the loose and a storm is rolling in...
The Ward Witch is the first book in a brand new contemporary fantasy series from the bestselling author of magical fiction, Sarah Painter.
*The Ward Witch is set in the same world as the urban fantasy mystery books, Crow Investigations, but it is the start of a separate series and can be enjoyed independently.
Praise for the Crow Investigations series:
'I'm a huge fan!' Charlaine Harris, #1 New York Times bestselling author of the Sookie Stackhouse novels

'My favourite new urban fantasy series, clever and twisty and deliciously magical, with a shivery sense of wonder that feels utterly grounded in its London setting. Perfect for fans of Ben Aaronovitch, Genevieve Cogman or Robert Galbraith!'
Stephanie Burgis, author of Snowspelled