Tsang’s arrest was pure luck. A Chinese detective returning from Macao on another case noticed a man dressed as a common laborer take a bundle of $100 banknotes from one pocket and put it into another. The detective questioned him about the large amount of money, but found his answers pretty thin. He was accordingly hauled to a police station, questioned further and searched. A letter found on him was eventually traced to John Tsang. Unofficially, the letter was said to contain instructions from a Communist espionage cell in Macao. The former Assistant Superintendent was thirty-eight years old, and so intelligent and popular that he looked to be headed for a top place in the department. Born in China, he had come to Hong Kong before the Reds ruled the mainland, joined the police in 1948 and rose rapidly from the ranks. He had gone to Cambridge University in 1960 for advanced studies, married while there, and returned to the colony in mid-1961. He was then one of the highest-ranking Chinese officers in the department. The nature of Tsang’s work gave him an expert’s knowledge of the colony’s defenses and internal security, information of obvious value to the Reds. His associates in the police force still doubt that he came to Hong Kong as a spy, believing that he turned Communist after he became established in the colony. His wife and mother remained in Hong Kong after his deportation. The Tsang case was also an embarrassment to Hong Kong Chinese who aspired to high office in the colony. It bolstered the anti-Chinese bias of old-school colonialists, giving them an opportunity to say, “See! When you give those Chinese a good job, they sell you out.” The stream of political abuse which Peking had directed at Hong Kong for a decade was superseded in 1960 by a stream of fresh water flowing at the rate of 5 billion gallons a year. On November 15, 1960, the two governments signed an agreement under which Red China was to tap its newly built Sham Chun reservoir, two miles north of the colony border, to provide an auxiliary supply for Hong Kong. The colony put up its own pumping station and laid ten miles of steel pipeline, four feet in diameter, to convey the water to its own large reservoir at Tai Lam, near Castle Peak. The water began flowing in December, 1960, and the arrangements for receiving and paying for it have proceeded smoothly since then. No one has assessed the symbolic or political significance of the deal, which meets only a small fraction of the colony’s water needs, but it disconcerts many American tourists. “Do you mean to tell me I’ve been drinking Communist water?” they ask. Most of the food they ate in Hong Kong probably came from Red China, but water is different. Some of them eye it suspiciously, as if they expected it to have a reddish hue or to contain traces of poison. The water is purified and filtered in Hong Kong, however, and thus far it has maintained a crystal-clear neutrality.