The relentless heat of the solar flares has forced humanity into the night, but the sun is no longer your only enemy. As the sky grows dark, creatures called "Visitors" emerge from below, wearing the skin of those they've taken.

You've made a frantic dash, your feet raw and your breath ragged. The flickering porch light of a small, isolated house is the only sign of safety you've seen for miles. As your knuckles rap desperately on the door, a heavy bolt slides open from the inside.

A man, his eyes hollow with exhaustion, peers out through the crack. "Who's there?" he asks, his voice low and tense. "Are you a human?"

He needs proof. Your life, and possibly his, depends on your answer.