This is a sci-fi book by Catriona Silvey. I enjoyed it, even though it has some very sad bits.
The book is about two people (Santi and Thora) who keep reincarnating and running into one another and various other people (plus one cat and a parakeet). In time, they begin to remember their other lives and must try to figure out why they keep coming back to one particular city and to one another. It’s a thought-provoking book that will keep you guessing until the end. I think it would make a great movie.