In 1942, in growing desperation at the progress of the war and fearing invasion by the Nazis, the UK government approved biological weapons tests on British soil. Their to perfect an anthrax weapon destined for Germany. They succeeded. Though the attack was never launched, the testing ground, Gruinard Island, was left lethally contaminated. It became known as Anthrax Island.

Now government scientists have returned to the island. They become stranded by an equipment failure and so John Tyler is flown in to fix the problem. He quickly discovers there’s more than research going on. When one of the scientists is found impossibly murdered inside a sealed room, Tyler realises he’s trapped with a killer.