Jamie Buxton picks July's sci fi and fantasy:  Stone and Sky by Ben Aaronovitch, The Man Who Died Seven Times by Yasuhiko Nishizawa, A Theory of Dreaming by Ava Reid

One of the plates Aaronovitch keeps spinning is Detective Peter Grant’s jazz-loving parents.

In this umpteenth addition to the Rivers Of London series, it’s clear there’s something jazzy in what he does: revisiting much loved tropes, yet always coming up with new and wonderful ideas.

Peter and River Goddess Bev are in Scotland for a seaside holiday but then a black panther appears, then a dead man with gills and, effortlessly, we’re off with a story that packs in oil rigs – sorry – platforms, psycho seagulls, greedy multinationals and sapphic mermaids.

The gang assembles once again, and we put the book down a little bit happier than when we started.

Detective fiction runs to strict timetables – not so much why-whodunit as when- whodunit. It takes a deliciously tricksy mind to turn that idea inside out and add a time-travel element. From the title onwards, this brilliantly intricate mystery has it all: a family gathering, a country house, the murder of a patriarch and a fortune to inherit.

Teenager Hisataro has not done badly from his habit of living occasional days multiple times – exam retakes for one thing. But his grandfather’s murder, replayed seven-fold, forces him to unpick the causes of an old family feud and work out who did the old man in.

Hugely entertaining and satisfyingly twisty.

Effy and Preston are both outsiders in the prestigious University of Llyr. Preston’s people are at war with the Llyrians and it’s only his brilliance that has secured him a place. Effy, meanwhile, is the first woman to be admitted to her course but she can’t stop rocking the boat.

Literature matters in Llyr – its founding myths are enshrined in epic poems, and the authors enshrined in glass tombs. So when Effy starts asking questions . . .

This emotional conclusion to A Study In Drowning centres on exclusion and bigotry but is fuelled by passion and determination. An academic treat, gowned in gothic darkness.