Second paragraph of third chapter:

In the future, there are many stories of those who go back. Those who go back to find a better time, and those who go back to change their own time. They go back to kill or to save, or for one to achieve the other. These stories centre on particular points in history, feature moral dilemmas and unintended consequences.

Brief but efficiently chilling story of a 1930s murder victim in Wellington, New Zealand, who comes back in three different alternative supernatural ways. One of the Sir Julius Vogel packet from 2020, which contains my dwindling pile of unread books acquired that year. You can get From a Shadow Grave here.