Scores of nations rush to join the Big Three in signing an atom-test ban agreement. The Kremlin is the setting for the historic event as the United States, Britain and the USSR agree to ban all except underground nuclear testing. Dean Rusk signs for the U.S., Andrei Gromyko for the Soviets and Lord Home for Britain as a jovial Khrushchev looks on with the U N Secretary-General U Thant.