More than a dozen spaceships have disappeared into hyperspace, never to return. The lost vessels include the Jason, the Starbird, and the Invincible. Everyone assumes they fell victim to some kind of mechanical failure.

The mystery deepens when the Invincible turns up drifting in space six months after it vanished. The ship's engines are undamaged, the hull intact — yet no trace remains of its crew or its two hundred passengers. Where have they gone?

Clearly something ominous has happened to the ship and the people on board.

Something in hyperspace...or somebody!