Book Review: Nightshade & Oak by Molly O’Neill

I received a review copy from the publisher. This does not affect the contents of my review and all opinions are my own.

Nightshade & Oak by Molly O’Neill

Mogsy’s Rating: 3 of 5 stars

Genre: Fantasy

Series: Stand Alone

Publisher: Orbit (February 3, 2026)

Length: 304 pages

Author Information: Website

Going into Nightshade & Oak, I was genuinely excited. I really enjoyed Greenteeth, and one of the things Molly O’Neill does so well is blend mythology and folklore into something that feels more personal and grounded instead of grand but distant. That said, it’s hard not to compare the books. This one had similar foundations when it comes to setting and themes, and on paper it should have worked just as well. In the end, though, I still liked it, just not nearly as much.

The story opens on a battlefield in ancient Britain, following a brutal clash between the Iceni tribe and the Roman army. Mallt Y Nos, goddess of death, walks calmly through the carnage as she has always done, guiding the souls of the fallen to the afterlife. As she stops to tend to the body of a woman, however, she senses something wrong. Unbeknownst to her, the woman’s sister had been nearby, attempting a desperate spell to save her gravely wounded sibling. Instead, the magic backfires, catching Mallt in its effects and turning her mortal. Furious at the loss of her divinity, Mallt now must contend with all the physical weaknesses of having a human body, leaving her no choice but to bargain with the woman responsible if she hopes to reclaim her powers.

That woman turns out to be Belis, the magically gifted warrior daughter of Queen Boudicca. In trying to help her sister Cati’s soul, which is lingering in an in-between state, Belis has unwittingly bound her fate to a goddess, albeit a now diminished one. Still, Belis knows Mallt holds the key to reaching Annwn, the Otherworld, and will need a guide to survive and navigate her new mortal reality. If they can endure each other long enough to reach the realm of the dead, Belis may yet have another chance to save Cati. Reluctantly, the two women form a tenuous alliance, their goals aligned for now. But as they journey across the war-torn landscape, their quest grows ever more complicated and dangerous, especially with Roman forces on their tail, determined to hunt down the last surviving daughter of Boudicca and crush the rebellion for good.

Like Greenteeth, this novel is heavily inspired by folklore but it also weaves in historical events and figures anchored in real history. The author’s affinity for the mythology behind Mallt Y Nos is obvious here, and I liked her take on goddess’s story. At the same time, I couldn’t help feeling that the historical framework boxed the story in a bit. In a way, Boudicca’s fate, and by extension her daughters’, is a weight that hangs over everything.

Tonally, Nightshade & Oak is also a lot darker. There is war and reminders of it everywhere, creating an undercurrent of inevitability running through the story. That itself is not a flaw, of course, but I did miss the slightly offbeat charm and warmth that made the plot and characters of Greenteeth so endearing. Sure, Mallt’s adjustment to mortality has its moments, especially in the beginning, but overall, she and Belis didn’t quite win me over the same way. Even as their relationship deepened into something more towards the end, there was still that disconnect, largely because I never felt fully invested in it to begin with.

To O’Neill’s credit though, the plot here is much more ambitious, not simply a “go here, fetch this/fix that, rinse and repeat as necessary, then go home” structure. The stakes begin remarkably high and they keep expanding as the story builds. While Mallt and Belis are indeed set on a quest, it’s one that grows ever more complex than it first appears. And I admired that. That said, parts of the middle dragged, and I found it more difficult to stay engaged during those sections. The added layers made it richer, but also occasionally slower and more uneven.

In the end, Nightshade & Oak is a solid read and there’s a lot to love here with its themes of myth and history, gods made human, and love shaped by war. And yet, I just couldn’t shake the feeling that something was missing, perhaps that extra spark or emotional pull to truly bring it to life. Even so, I’ll absolutely keep reading whatever Molly O’Neill writes next, the promise of creative ideas blending history and fantasy always drawing me back.