A new Victorian mystery featuring the popular Detective Best. After bombs explode in London, Best is sent to Paris, where Irish Americans are plotting their next 'outrage'. There, he encounters a gentleman who says he is helping the French save their plague-ridden vines. But is he who he claims to be? What happened in the blood-soaked railway compartment? And how does it connect with the fate of a young man who may have been lured by a heartrending advertisement in a daily newspaper?