Five youths are sentence to staying at a dude ranch called the Three Silver's Ranch, to learn respect and work together or be sent to juvie.
On the outskirts of the small town is a military installation that works on the latest drone technology. One group of drones are used for stealth pin point damages. They are the attack drones used to kill or destroy instillations.
A different series of nanorobot drones are microscopic versions and are used to go inside the wound and stabilize wounded soldiers in battle if the medics can't get to them in battle fields. Think of Fantastic Voyage.
Chad Iverson 25, spokes person for Swarm Incorporated and Holly Courtesan, 22, associate personal advisor, head a seminar for their latest breakthrough technology of micro-nano drones. Military, politicians, medical departments and other dignitaries are there to see the demonstrations. It's a hit and people are swarming to buy it.
Meanwhile, a massive sun flare causes the programing to shut down and scrambles the informations in the system. Instead of saving the soldiers, the nano-microbots reanimate wounded and dead people and turns them into killing zombies that wipe out the town and surround the dude ranch. The kids who can't stand each other now have to work together to survive or die.
Meanwhile, the technicians who designed the nanobot system struggle to find a way to shut down the program only it learns to outsmart the creators. The only way to shut it down is to get a virus program, code named Cardiac, into the system. It's a fight to the end as it spreads across the globe.