The French author Fred Vargas has won the top prize in crime writing, the CWA International Dagger, a record four times. Now she’s come up with another contender, the breathtakingly original This Poison Will Remain... The poison in question is the venom of the recluse spider, a shy creature whose bite causes a painful swelling but isn’t usually fatal. Yet three elderly men have died after being bitten, prompting speculation that the venom has mutated because of climate change.... It is the starting point for a wildly inventive plot that puts Vargas’s real-life expertise (she is an archaeologist) to brilliant use.