It’s April 2020 and Edinburgh is in lockdown, but that doesn’t mean crime takes a holiday. It would seem like a strange time for a cold case to go hot — the streets all but empty, an hour’s outdoor exercise the maximum allowed — but when a source at the National Library contacts DCI Karen Pirie’s team about documents in the archive of a recently deceased crime novelist, it seems it’s game on again. What unspools is a twisted game of betrayal and revenge, but no one quite expects how many twists it will turn out to have.