"Scene" of the crime? Never has the term been so apt!

Paris, 1631: a series of showstopping murders have shaken the capital, each perpetrated beneath the proscenium arch right in the middle of a play. At the scene of each crime are found two tarot cards and screeds against Renaudot, personal physician to Cardinal Richelieu, who is trying to launch France's first newspaper. Is it a rivalry between Parisian theater troupes? Or a means for the murderer to get at Renaudot, and indirectly the much-feared Cardinal? And how has this killer manage to multiply their misdeeds when all the capital's eyes are upon the stage?