"Leave quickly and come back late") is a 2001 novel by French author Fred Vargas.

Joss, a middle-aged former Breton sailor, begins to succeed in reviving the old family trade of town crier in modern-day Paris.

Business is good, since people gladly pay five francs to hear their rants and nonsensical messages in parks and squares; every so often, ominous cryptic messages announcing the return of the plague will also be part of the day's requested cries.

At the same time, chief inspector Adamsberg is surprised as a distressed woman describes that all her apartment building's doors, except one, have been marked with a large inverted "4" in black ink with the inscription "CLT."

Inspector Adamsberg must lead an investigation that takes him through a juxtaposition of 15th-century Europe and modern-day France...or does he?