Three inept night watchmen, aided by a young rookie and a fearless tabloid journalist, fight an epic battle to save their lives. A mistaken warehouse delivery unleashes a horde of hungry vampires, and these unlikely heroes must not only save themselves but also stop the scourge that threatens to take over the city of Baltimore.

While driving to Las Vegas for the bachelor party of her sister Melissa and her fiancé Bobby, Kayla stops the car in the gas station to meet her date, Nik, a guy she met on the internet. Nik convinces her to take a secondary road under the protest of Bobby but the car breaks down. They find a house in the middle of nowhere and decide to take the car parked in the house's garage to the next city, and return with a rented car to pay for the damages provoked by Nik; Melissa leaves her cell number. However, they discover that the owner of the place is the sadistic truck driver Rusty Nail and they have to pay a high price for what they did.

In 1948, a group of miners finds a gallery full of emeralds in a salt mine in Switzerland, but they are attacked by giant black beetles and only one of them survives. In the present days, the explorer John Palmer is ready to take vacations in Greece with his family when he is contacted and invited by a stranger called Vincent to lead his team in an expedition into a mine in Switzerland. In return, Vincent offers a large amount to John and the cottage nearby a lake and the entrance of the mine for his family to spend the vacation. John accepts the offer, and while leading the group underground in the tunnels, he finds that their ambitious leader Marcel is a very dangerous man. When John meets giant black beetles in the cave, he orders the group to return but Marcel threatens the safety of his family, forcing John to lead the team to the deep location of the emerald mine.

In 1947, noted Satanist Aleister Crowley dies. In Cambridge, 43 years later, with the help of a computer, Crowley's spirit takes over the body of Haddo, a mild-mannered, stuttering don. Over four days, as Crowley prepares for an occult extravaganza, bodies pile up, Crowley's elect engage in rites of passage, and Lia, a red-headed campus reporter, sniffs out a story that puts her in grave danger. Mathers, a scientist recently arrived from Cal Tech, may hold the key to her destiny.