“I didn’t think private investigators had cars like this,” says Mina. His receptionist is driving; they face each other in the back.

“The locked-room mystery,” Inspector Dracula muses, “is so important to fiction, and so rare in reality, that we must consider this scenario a deliberate recreation. The first detective story, by Poe, or Conan Doyle’s ‘Speckled Band…’ Carr’s The Hollow Man has perhaps the definitive overview, and indeed some of those conceits are more plausible than the book itself.”

“Which one involves the air vent?” asks Mina tartly.

“Oh, never mind that,” says Dracula, “your ‘guard’ has a twin.”