It’s probably premature to review this first volume before having read the rest – although only two have so far have been published in English, the third is due in November, the fourth in April next year… and to date only six of the planned seven have been published in the original Danish. (I should point out it’s not On the Calculation of, volume 1, but On the Calculation of Volume, part one.)

The basic premise is: antiquarian book dealer Tara Selter, resident in France, visits Paris to purchase new books for the home-based business she runs with her husband. While there, she wakes up one morning and discovers she is reliving the previous day. In fact, every day from that point on is 18 November. Just like Groundhog Day.

She returns to her husband, and explains the situation to him. But the following morning… is 18 November again for her, and she has to explain all over again. And again. And again. While she is stuck in time, he continues travelling forward day by day.

Tara tries several different ways to live – spending the day over and over again with her husband, living in his shadow as he repeats his 18 November… She discovers that any changes she makes carry over to her next 18 November – so if she takes food from village shops, their stock diminishes on the one day she inhabits. She explores the limits imposed on her as he lives the same day over and over again – some items return back to the beginning of the day with her, some are lost to 19 November, and so on.

It’s all very cleverly worked-out, and written in an appealing flat lucid prose. This first volume (did you see what I did there?) is Tara exploring the “rules” which seem to govern her situation, both in her home village and in Paris. She inevitably grows distant – first from her husband, then from other people, then from her own life. The novel – it’s short, only 166 pages – is almost entirely set-up. But then there are seven books (each one also short) in the series. Nonetheless, On the Calculation of Volume I (2020, Denmark) doesn’t feel abrupt or incomplete. It reads like the first step on a journey toward the solution of an impossible mystery (although the shadow of Groundhog Day does lie a little heavy across it).