Jason Gedrick and a small group of Marines are stranded in the remote Afghan desert. But it ain't the Taliban that's worrying them, it's these giant refugees from Tremors. In fact the big worms prove to be an ally of sorts by doing better against the Taliban than themselves but battling these enemies is something not covered in their training.

On her first trip to Paris, a young woman hits a party in the Catacombs, the 200-mile labyrinth of limestone tunnels under the city that's lined with the remains of 7 million people. Separated from her friends, she becomes convinced that someone or something is chasing her.

After receiving mysterious empty packages inside his apartment, a young computer-programmer (named Simon) begins a personal investigation into their origins. This leads him to discover his odd and eccentric neighbors; an artificially intelligent robot-head, named Adam; a virtual-reality sex game; and a possible corporate conspiracy. As the story progresses, Simon's grip on reality becomes more and more tenuous, while his craving for Nature Fresh milk becomes almost unbearable. Is it all just in his mind, or is something more sinister happening here?

Picking up immediately where Anaconda 3 left off, herpetologist Amanda Hayes finally learns her employer Murdoch's true colors when he hires a doctor to harvest a fresh supply of blood orchids to experiment with the regenerative nectar on a baby snake in order to seek treatment for his own terminal illness. Amanda is forced to secretly bring together another team of scientists whom face off against a heavily armed squad of Murdoch's men to steal the coveted orchids before the killer Anaconda hunts both parties down.