It's been thirteen years since the robotic killing machines known as Screamers destroyed the human population of Sirius 6B. But now the distress signal brings a team of resuers to the supposedly abandoned planet. Can it be a long lost colony of human survivors? Or have the Screamers evolved into something even more sinister...half-man/half-machine hybrids that need to escape Sirius 6B to finish their mission:the complete annihilation of the human race?