The university town of Oxford is the scene of first one gruesome murder followed quickly by a second. Both murders were of young women who had their throats slashed, a body organ removed and a replica ancient coin placed in the wound. In each case the scene was similarly devoid of forensic evidence and the incision looked to be performed with surgical precision. The bizarre murders suggest that this is no ordinary killer and there is every chance that the first two will not be the last.

Laura Niven is in Oxford, visiting from New York, gathering research material for a novel she is in the process of writing when she becomes drawn into the case. She has been staying with the father of her daughter (their domestic situation is unusual) who happens to be a police crime scene photographer and she was with him when he was called to the scene of the second murder.

The distinguishing similarities of the murders piques her interest and she begins tracing a few clues that lead her down a mystical path of astrology, alchemy and a so-called scientific experiment that ultimately seeks the Philosopher's Stone. Her research for the forthcoming novel is quickly forgotten and she becomes completely focused on a far more fantastic scenario.

The murders that are taking place in present day Oxford mirror those that were committed at various times throughout the town's history. We trace back to the 1690's, to the existence of a society made up of the period's scientific elite known as The Royal Society and, in particular, Isaac Newton, who was driven by the lure of the Philosopher's Stone. The link between astrology and the murders holds true for both time periods with every murder committed on a significant day in the astrological cycle.

Upon unearthing the startling connections, Laura has the difficult task of convincing the police detective in charge of the investigation what could be happening and that more murders were due to follow if her theory proved to be right. Although not expressing outright scepticism the detective is doubtful, the possibility that the murders were part of such an outrageous experiment just seems too implausible to follow. Laura is left to do her own investigating which can only lead to the most extreme dangers.

Equinox is an absorbing mix of legend, mysticism and murder comparing a present day serial killer hunt with similar events that took place 3 centuries earlier. The story flows nicely with smooth transitions made between the two timeframes, putting into context the reason why things are happening as well as foretelling coming murders. The story tends to build in intensity as it becomes clear that the murders are far from your ordinary serial killer slayings. Falling under the amateur sleuth category, Laura's investigation is hampered by the fact that she lacks any kind of authority and this tends to slow the pace a little. But this is compensated for by the tension that mounts as she puts herself and her family in danger.

The climactic ending to the book is very reminiscent to a few scenes from the Indiana Jones movies, even going so far as to mention them. And, although it makes for a hectic, heart-stopping finale, one couldn't help reflecting that this kind of thing has all been done before. If the book has a failing, then this lack of originality would probably be it, and even then, it doesn't detract from the overall enjoyment.

I thought Equinox was an gripping book that cast a new spin on the serial killer scenario. Ancient legend, scientific enterprise and horrific murders drive the story to a shocking climax. If you're looking for a great book to take away on holiday to relax on the beach and lose yourself, then this is your book.