The publisher classifies this book as fantasy, but as it is based on one of the classic SF tropes, time travel - and this is done by technology, rather than magic - it can sensibly be classified as science fiction. The book features St Mary's, an institute of history attached to a fictional university, where the historians research the realities of history using time machines. While not a particularly original idea - Bill and Ted did their history homework this way a long time ago - it's quite nicely set up with a Time Police organisation that is technically on the same side as the historians, but in practice is often in opposition, plus a couple of dastardly time travellers who are intent on messing with the St Mary's bunch, up to and including committing murder. I did have a slight problem coming to Plan for the Worst as it's book 11 in a series - I sympathise with Jodi Taylor in trying to make the opening accessible to someone who hasn't read the series bef...