When the grail is stolen from the British Museum, the Drews are invited back to Trewissick to help Gumerry retrieve it. But with only a week’s holiday – and a strange boy called Will Stanton tagging at their heels – how can the children find the space and secrecy to complete their quest?

The opening sentence sets the scene: the grail has been stolen. We are plunged back into the world of the Drews, joining the three children exactly where we left them – at the British Museum. It’s a clever device: in one swift set-up we move out of the legendary canvas of The Dark is Rising and back into the more human world of middle-class adventures.

I think there’s a shift in prose style between the two modes, which isn’t to say that Greenwitch isn’t beautifully written. The clear, sharp sentences capture images quickly and economically: two elderly ladies rubbernecking at the Museum are perfect snapshots of their era, their hats a pink pyramid and a yellow flowerpot. They think they’re the height of fashion; the children (and these days, the modern reader) clearly find them faintly ridiculous.

An aside from Jane – that they can’t even tell Gumerry about the theft as he’s on sabbatical and was too busy even to send a card at Christmas – is a gift to the reader. We, of course, know exactly what was keeping Merriman Lyons busy through the winter. Old Ones may be able to step between time periods, but they don’t have the timey-wimey sophistication of hopping back into last month to pop something in the post as an alibi. He can be forgiven for not remembering all the social niceties.

When Gumerry inevitably appears, it is to tell them that they are bound up in the chain of events and needed by the Light – and that they must remain ignorant of the bigger picture. The children’s response neatly encapsulates their characters: Jane, always the most insightful of the siblings, is thoughtful and worried for Barney’s safety; Barney throws a childish tantrum at being treated like a child; and Simon is keen to be a hero, having already forgotten how close he came to giving up last summer.

Coming hard off the back of The Dark is Rising, this scene makes Merriman a more shadowy figure. I now know and fully understand what Merriman is willing to risk, and how limited the protection he can offer will be. He is subtly misleading them and asking them to work on faith (and does so knowing that they will). Merriman is far more morally ambiguous than the Drews realize, but only Hawkin could expose him. Needless to say all this was lost on me as a child.

The action swiftly moves to Cornwall, driven by the sort of coincidence that the books thrive on (it’s far too easy to assume Merriman is the architect of Bill Stanton’s UK trip, until Will’s gift for the Greenwitch makes it clear he was slightly too well-prepared for a little boy who supposedly had no plans for Easter). We once again find the Drews waiting at a train station – and again they go largely undescribed. They are every-children, the stand-in for the reader. We learn only that in the past 6 months Jane has shot up to become as tall as Simon; Simon is Will’s age; and Barney – as we already knew from the previous summer – is very blond.

If Over Sea Under Stone was a grail quest – ultimately hinging on the courage of the boys and Barney’s purity of heart – Greenwitch centres on Wild Magic and women’s rites. This is Jane’s book, and I like it all the better for it, although I feel a little sorry for Simon – less of a bully and slightly braver here, he’s still given very little to do. Jane is the one invited to the making of the Greenwitch, and it is her compassion that is critical to their quest. I love that the ceremony – which could have been portentous, mythical, on a par with Will’s experiences at midwinter – is almost entirely mundane. The village women drink tea and swap gossip whilst weaving together the branches to build their effigy; the village girls ask for handsome husbands; Jane falls asleep. This is almost a domestic sphere, an annual social gathering, its deeper resonance almost unrecognized (almost – the village carefully exclude outsiders, refusing to allow it to become a tourist event).

Jane’s unintentional connection with the creature of Wild Magic always reminded me of Susan in The Moon of Gomrath, discovering that Angharad’s bracelet was a double-edged gift, or Eilonwy coming to understand that she cannot dismiss her heritage as a daughter of Llyr. Perhaps it was only the books I chose to read, but the theme of women being connected to uncertain, less controllable magic runs strong through the books I remember best. Even Lucy Pevensey is a mystic.

Yet the wildest magic is reserved for the painter – an ambitious, lonely, vicious man hoping to entrap the Greenwitch with his talents and wrest her secret from her. I can’t help myself by this point: I want to know more about the Dark. We are never even told his name. He is another casualty at the hands of a higher power: there was no pushing away the unreasoning rage of the Wild Magic as it made a scapegoat of its attacker.

There are a number of throwaway lines in Greenwitch that caught me, and this one – with its implication that while he provoked the Greenwitch, his end is neither deserved nor entirely personal – moved me. So did Will’s reflection that men mostly kill one another without any intervention by Dark or Light. The bleak subtext sets the tone for The Grey King.

A couple of final thoughts before I stop resisting the urge to pick up the next book: firstly, the set pieces here are as spectacular as any in The Dark is Rising. Will and Merriman dive into the deep seas, giving us a glimpse into a realm that is beyond both Light and Dark. The realm of Tethys is cold and terrifying beyond measure, the White Lady of the sea a force that even the Light must fear, and which it cannot command. Nonetheless, the dark and cold of the lightless depths have no affiliation to the Dark – it is neutral and wild. Cooper chose brilliantly in refusing to describe her ocean goddess: Tethys is the sea, a disembodied voice and an immutable will without any human aspect. It’s chilling stuff, and it sets up the second great set piece: the ghostly nightmares of the Wild Magic running amok in Trewissick, which still give me the shivers.

My other thought is of the Light. If we set aside what we’re told and look at only what they do, the Light is less than comforting. Merriman is honest with the children from the start that he’s keeping secrets (both good and bad in itself); but in refusing to let Will identify himself as of the Light he robs the Drews of significant protection. The painter might never have had the opportunity to ensorcel Barney had Simon been willing to let Will keep them company; which leads me to recall that without the painter’s actions, the Light too would be ignorant of the fact that the Greenwitch can be bound by the spells of Mana, of Reck, and of Lir. Are the Drews bait?

As soon as Merriman and Will hear Simon’s account, they take off for the deep ocean, leaving the traumatised Drews beside themselves at the sight of their companions throwing themselves off a cliff. Captain Toms is as casual as the painter in wiping the children’s memories clear – rather than providing explanations. Perhaps ignorance is a form of protection – but this doesn’t cross Captain Toms’s mind. He simply forestalls a scene by making them forget, and preserves the secret of the Old Ones. Normal people are pawns to both the Dark and the Light; and I’m naturally suspicious of ‘it’s for your own good’ as an explanation.

…which brings us back to Merriman Lyons. At the end, Merriman is dismissive when Jane is upset at his destruction of the Greenwitch’s secret. He has got what he needed from it, and to his mind it was never truly the Greenwitch’s to keep – it never occurs to him to offer to return it (even though it’s clear that the Greenwitch would take it beyond the Dark’s reach) or to offer anything quid pro quo. Points for being single-minded, but it’s all rather entitled and lacking in compassion. Thankfully Will is around – and, err, terribly well-prepared (I’m assuming he stepped out of time to care of that errand) – to make amends.

All in all – I loved this book, and I love the way it handles the emerging themes of loneliness and isolation (and how these affect decisions and behaviour). I also, frankly, love being able to read far more into the behaviour of the Light than I think is intended – I’m pretty sure I’m over-interpreting, and I don’t care. It makes the experience that bit richer for me and makes up for my ongoing adult frustration that the narrative never lets us glimpse what the Dark are actually about.