The skelkrins. Predators from deep space. Creatures of claws, fangs, and unending malice. They swarm across the galaxy, slaying all in their path. Planets burn in their wake. And now they're heading to Earth.Raphael "Riff" Starfire commands the Alien Hunters, a group of scruffy mercenaries. Galactic pest controllers, they mostly handle small critters—aliens that clog up your engine pipes, gnaw on your hull, or burrow through your silos.Riff and his crew have never faced anything like the skelkrins before. As these cosmic killers invade our solar system, will Riff be the one hunting aliens...or will aliens hunt him?