Have Mercy on Us All

About “Have Mercy on Us All”

Several strange black-paint symbols appear on apartment doors across Paris. The mark resembles an upside-down "4" with two bars on the lower leg, followed by the letters "CTL." At first glance, it seems like the work of a graffiti artist. However, Inspector Adamsberg recognizes it as a sinister threat. Meanwhile, Joss Le Guern, a street announcer, receives strange messages in his mailbox. The notes are written in Latin or from old texts and include payments far higher than usual. Some suggest a prank, others a madman. All of them predict the return of an ancient plague.