Unholy Island, the mostly forgotten neighbor of Holy Island, is a strange place that everyone quickly forgets, except the few granted sanctuary there. Esme Gray escaped an abusive marriage and found her way to the island because their previous Ward Witch had died, and ridiculous as it seems, it's now her job to run the guesthouse while she maintains the island's protections. Luke Taylor has been searching over a year for his missing twin brother and follows a rumor that leads him to Unholy Island, where a suspicious murder leaves the island in need of a Book Keeper, which he finds a strange term for someone who runs a bookshop. Then there is the kindly old mayor Tobias who was the island's first resident so long ago he barely recalls his true nature. All three of them are weaker than they should be, but together they form a tenuous bulwark against the end of the Earth.
The Ward Witch: Esme has spent the past seven years running the bed and breakfast that came with her post as Ward Witch. She's still not sure she believes she's an actual witch but it's true that tourists never stay on the island more than two nights and almost immediately forget it after they leave. That's until Luke shows up looking for his twin brother and shows no sign of leaving. Since new residents are usually only accepted by the island after someone dies the residents are unhappy. They're a strange group and it's considered impolite to ask someone about their past, because there is at least one murderer among them, or what they are because some are quite obviously not generic humans. There's a strange teenage boy who's oddity could be because he's the only child on the island but feels like it's more. The three sisters that absolutely no one thinks are human and everyone avoids because they are seriously disturbing. There's also the Book Keeper Avril who's shop rearranges itself with a door that won't open if it doesn't like someone who's found dead on the beach only a few days after Luke arrives. With only thirty residents and no tourists that time of year it's a short list of suspects with Luke at the top of the list.
The Book Keeper: With Avril dead the eldest of three sisters, Bea, decides Luke will take over that role if the shop accepts him. It let's him in the door which is good enough for most residents. But Luke still needs to find his brother no matter how appealing it is to give up and unfortunately he's not the only one looking for Lewis or at least someone else to pay off Lewis' debts. Since he's now the Book Keeper, whatever that actually means, he gets a little help from his new neighbors. Turns out the guy who runs the General Store isn't actually mute and the fisherman who looks more like a hardened criminal does in fact know how to make people disappear. Things take a more serious turn when an shipment of books, that no one ordered, contains a cursed book that nearly kills Luke. Turns out people who buy and sell arcane books, an unexpected part of Luke's new job, are dying horribly all over Scotland and Esme is convinced it has something to do with yet another person who manages to stay on the island past two days.
The Island God: Given the title and what we've seen of his thoughts this book was obviously centered around Tobias who had been an intriguing character from the beginning. The first two books seem to be more about Esme and Luke coming to terms with their history and their new places among the islanders but now we discover that Unholy Island and especially the Ward Witch are really protecting the entire Earth. I recalled only a single vague reference in the first book about there being an even smaller island past Unholy Island that was rarely visible through the mist. Suddenly it has not only become extremely visible but a small fire was spotted on the shore. The only structure on that island is an ancient tomb that contains a portal open to other dimensions. Tobias goes to investigate but he has spent too long living as a human that he's too slow to save himself from being grabbed by the portal. He has traveled between dimensions before but that was when the Earth was much younger and he has forgotten how. In the meantime Lewis has been found at last but he isn't happy to see Luke and is obnoxious in general. Then Lewis suddenly steals a boat and goes to the evil island. Suddenly, everyone loves him but Esme. Luke is glued to Lewis' side, Tobias is missing, Bea is unconscious as her spirit searches for Tobias, which leaves Esme to fight alone against Lewis, or whatever he has become. Then the Wards break...
This trilogy is a bit more subdued than most that fall in the urban fantasy genre. The first two books are as much mystery as they are fantasy with light romance thrown in. While the books mostly focus on Esme and Luke the PoV shifts around to most of the villagers from time to time so you get to know everyone and they all have their secrets and things they would rather forget as you might expect from people who sought sanctuary away from the world. The main chars are deep and the side characters are intriguing. The plots are a bit weak since solving the problem and revealing the villain are understated. The third book has the most drastic plot elements and I would have preferred more of Tobias' back story, more about the peril of the portal, and less about obnoxious Lewis and his new "power". While the Lewis situation had the potential to devastate the world it wasn't an immediate doom and probably wouldn't have been truly apocalyptic because this small group are not the only magical people in the world. I am certain of that because this is set in the same world as Painter's Crow Investigations series.
I think my thoughts are in line with other reviews. Katie Villa was well rated as the narrator but few reviews specifically mentioned the narration. She has a long list of well received credits.