With Ed staying a little way behind to keep Peter covered, they slowly made their way up to the road again. Karen was standing by the wagon in bare feet, jeans, and the white puffy-sleeved shirt she usually wore in bed. When she saw them coming – Peter and Della, Shearson and Ed, she couldn’t work out what had happened at first – who had captured whom. But when Ed said, ‘It’s okay, Karen. Everything’s fine,’ she came walking across the blacktop bare-footed with tears running down her cheeks.

‘Oh, God, I was frightened,’ she said, holding Ed’s arm. ‘Oh, God, I can’t tell you how frightened I was.’

Ed put his arm around her and held her close. Della, beside the wagon, gave him a mocking little raise of her eyebrows, and a smile that could have meant anything at all.

Seven

During the weekend, an intensive search by fifteen volunteers from the St Louis Fire Department had revealed five radioactive isotopes in grain elevators along the waterfront, and ‘perceptible’ radioactivity in almost every grain and flour store within a six-mile radius of the city. The isotopes had been taken to the National Nuclear Research station in Kokomo, Indiana, where tests showed by late Monday afternoon that each of them contained over 4000 curies of radioactive cobalt-60.

At 11.43 p.m. on Monday night, the President was informed of the discovery, and he issued immediate instructions for the contaminated cereals to be destroyed. They were to be taken out to sea and jettisoned in deep water off Miami, under the supervision of experts from the Navy, the Bureau of Atomic Energy, and the FBI. The President emphasised that it was ‘essential, at this time of threatened shortage, not to let these radioactive foodstuffs go astray, or to fall into the hands of those who might not be so scrupulous about where they go to.’

Geiger-counter searches of grain elevators and flour warehouses all over the country were put into motion a few minutes after midnight, and by seven o’clock on Tuesday morning, officials had discovered isotopes in Chicago, Duluth, Milwaukee, and Seattle. Whoever had planted the isotopes had shown no discrimination. They were found in grain stores at breweries, amongst oats and bran in animal-feed factories, and in flour warehouses at kosher bakers. The nuclear laboratories were unable to tell where the isotopes had come from, since their casings bore no serial numbers or manufacturer’s marks, but three out of the seven analysts working on them expressed an opinion that the cobalt was of European origin.

‘We are being attacked from without, rather than within,’ said the Director of the FBI, Charles Kurnik. ‘I don’t think we need more than three guesses to answer the question by whom?’