The next day, she drags him to dinner in a novelty restaurant called Toujours Nuit ("Always Night") because the dining room is kept in total darkness, and all the waiters are blind.

Captain Stottlemeyer and Lieutenant Disher fly in overnight from San Francisco because the skull found in the catacombs has been identified through dental records as belonging to Nathan Chalmers, the architect of a Ponzi scheme whose victims included many of California's wealthiest and brightest.

It was believed that he committed suicide ten years ago, but the skull proves that he faked his death and escaped to Europe, a case embarrassing enough to send the two American detectives to Paris on the Commissioner's orders, in order to give credence to the claim that the police never closed Chalmers's case and their investigations led to the skull's discovery.

In addition to the TV and horse manure, Barlier owns a putter with a pattern matching the wound in Chalmers's skull and dinner plates taken from the trash at Tourjours Nuit.

He killed her and lead Monk and the other detectives to Barlier's home in the catacombs, inadvertently confirming that he knew the way there, and thus could have planted the putter and dinner plates.

Bisson also owns a set of night vision goggles for his sojourns into the sewers, while Barlier does not, and so could have found his way to Dupon in the darkness of Tourjours Nuit.

Between solving two murders, and getting to drive a motocrotte during his off-time, Monk is satisfied, and admits that their enforced French vacation has had its points of success.