The Plague Road — L.C. Tyler

A politically sensitive murder is detected amid the chaos of a deadly plague in this “stellar . . . well-crafted” mystery set in Restoration London (Publishers Weekly, starred review).

It's 1665, and the Black Death has London in its hideous grip. It's bad news for everyone . . . almost. For a mysterious killer, it presents an opportunity to hide a dead body among a city full of them. But as corpses are collected and brought to the burial pit, one of the bodies is revealed to have a knife in its back.
When the victim is identified as an agent of the King's spy network, fixer John Grey is called in to handle the situation -- and, above all, locate the sensitive documents the agent had been carrying at the time of his demise. Now Grey must navigate the deadly pestilence as he uncovers a potentially explosive conspiracy.