"Wasn't dead yesterday," said his father. "Maybe that eruption was radioactive." Burl looked up sharply. "I'll check the Geiger counters, Dad. Something's blocking reception, something strong and powerful to interfere with this set." But when he returned, he had to admit he had found nothing. When the Sun went down, they retired, for the temperature drops swiftly in the high, thin air of the Andes. In the rest of the world people watched their color-vision shows without interruption. Reception was good with the Moon base, the space platforms had no difficulty making reports, and the radio news beamed out as usual. In Lima, there was a little static, and direct transmission with Brazil seemed partially disrupted, but that was all. In the following five days, the Denning expedition had managed the difficult climb over the next range of mountains and had come down in the high plateau valley between. In this same period, the world began to realize that the dimness of the sky was not a temporary phenomenon. Weather stations noted that the past few days had all been several degrees under the average. Reports had come in that farmers were querying the unusual drop in the temperatures at night. And astronomers, measuring the surface heat of the Sun, came up with strange discrepancies from previous data. One astronomer communicated with another, and a general exchange of advice began. In a short while, a communication was laid on the desk of the President of the United States, who scanned it and had it immediately transmitted to the Secretary General of the United Nations. The Secretary General circulated the report among the scientific bureaus of all member nations, and this led in turn to a meeting of the Security Council. This meeting was held in quiet, without benefit of newspaper reporters or audience. There was no longer any doubt. The radiation of the Sun reaching the face of the Earth had decreased. The facts were indisputable. Where a day should have registered, in some places, at least 90° in the Sun, a reading of only 84° was noted. Measurements definitely showed that the face of the Sun visible to man on Earth had dimmed by just that margin. This might not prove serious at first, but as the scientists called in by the Security Council pointed out, it promised terrible things as the year went on. A difference of five or ten degrees all over the Earth could mean the