crystalline structure, dividing and mutating simultaneously, so that normal earth checks and balances fail to stem its multiplication.

Experiments show that the infant and the old man survived because the organism grows only within a narrow pH range -- if blood is either too acid or too alkaline the organism, code named Andromeda, can't survive.

An emergency warning bell sounds. Contamination is spreading. A polycron seal deteriorates and Dutton is trapped in an autopsy room. He is saved from death by breathing as fast as possible, inducing respiratory alkalosis.

Andromeda mutates to non-infectious form but is still causing gasket seal degeneration. Emergency siren sounds.

Five minutes to self-destruct.

If the bomb goes off there will be a thousand mutations of Andromeda. It will spread everywhere; man will never be able to get rid of it.

But Level V is now sealed off. Only Hall, equipped with the turn-off key, can halt the self-destruct. He shatters a service port window leading to the lab's central core. Since Level IV is contaminated he tries to climb to Level lII.

His progress is hampered by laser beams and deadly gas, automatically triggered to prevent escape of lab test animals. With scant seconds remaining, he cancels self-destruct.

The Andromeda super-colony, still mutating, fails to turn lethal again. Cloud-seeding procedures are used to carry the organism into the ocean so alkaline reaction will kill it.