This book is so many things: a work of fantasy, a literature review of every major work about the journey into hell, a love story, a wicked academic satire, a philosophical musing on the meaning of life and a love letter to Cambridge. Or perhaps the title itself, which means both a retreat to the coast, in this case to the banks of the River Lethe, as well as a descent into Hell. Like its Oxford counterpart before it – Babel – its central leap is that magic (here referred to as magick, ie the academic discipline stretching back to the alchemists and beyond) sits alongside the other subjects at Oxbridge colleges. The magic we see practised, taught, researched and dissertationed feels very mathematical. So we are unsurprised to hear that the mathematicians hate the magicians.

Alice Law is the Chinese-American PhD student of the great Jacob Grimes, who (accidentally?) sends him to Hell and then, with her once-friend-now-mortal-enemy and Grimes’ other PhD student, Peter Morgan, sets out to bring him back. So that Grimes can pass their dissertations, because that’s a good enough reason to journey to Hell and sacrifice half of your future lifespan. And so the quest begins.

There is quite a bit of mathematical fun had despite Alice not really knowing any mathematics, including an Escher Trap, a Penrose Staircase and a hyperbolic geometry which makes the quest very heavy going at times. And so many logic puzzles. Comedy and total horror are nicely juxtaposed throughout, as Alice and Jacob get to understand each other better and start to wonder whether Grimes is worth it after all.

The constant side swipes at the life of a junior academic are often hilarious. Magicians in training are apparently told by all their professors that they should consider careers in other fields or “alt academia”, as they called it:

“…no one really meant it when they said alt academia was just as prestigious (or, more commonly, that there was no shame in it, really). They meant it even less when they emphasized that alt academia paid better, had kinder hours, was less stressful, gave you better job security, made you happier. Oh, magicians do really well in consulting, they said. Employers like critical thinking and problem-solving skills, they said. Fewer people die in industry, they said.”

The most enigmatic character is their not-quite-constant companion, Archimedes the cat, who guides them when he feels like it. All the way through all eight of the Courts of Hell, alongside and across the Lethe and finally to King Yama’s Domain, on a journey which threatens to destroy Alice’s very sense of self. Her catechism, which she repeats at stressful moments:

I am Alice Law I am a postgraduate at Cambridge I study analytic magick

Alice has always felt that if she could just hang on to the delusions which had got her this far until the end of her PhD all would be well, but these turn out to be precisely the things she needs to confront if she is ever going to get out of Hell.