In 1966, Moorehead and his wife, younger son and daughter (Caroline Moorehead) made what became for him the first of an annual series of visits to Australia. There he had completed a television script for his manuscript "Darwin and the Beagle", but tragedy struck before the book was published. That December, suffering from headaches, he went into London's Westminster Hospital for an angiogram which precipitated a major stroke. It was followed by an operation, in which brain damage occurred, affecting the communicating nerves. At 56, Moorehead, one of the great communicators of his time, could neither speak, read, nor write.