“In his veins, I found the venom of the Mamba du Mal, one of the world’s most poisonous snakes.” “Does this mean that there’s a poisonous snake loose in this house?” Mr. Poe asked. “No, no,” Dr. Lucafont said. “The Mamba du Mal is safe in its cage. It must have gotten out, bitten Dr. Montgomery, and locked itself up again.” “What?” Violet asked. “That’s a ridiculous theory. A snake cannot operate a lock by itself.” “Perhaps other snakes helped it,” Dr. Lucafont said calmly, sipping his coffee.