Dr Damon Zeno: microbiologist... American defector... a dedicated and dangerous enemy. That was about all Nick Carter knew about the man he was hunting - except that Zeno was set up in a secret lab, perfecting a chilling new weapon for the destruction of the United States.

The weapon was the 'Omega mutation' - a microscopic bug. It multiplied quickly and it could not be destroyed. It would kill a man in a matter of days. Zeno planned to turn it loose in the United States - and Nick Carter had no choice but to destroy Zeno before 'Omega Day'.

Soon Carter was in Tangier, hot on Zeno's trail - with his automatic snug in its holster... a beautiful girl named Gabrielle close at his side... and a death trap waiting for him at every turn.