Standing on the shores of the East End, you can see across the water to some of Long Island's greatest treasures, tantalizingly close yet forbiddingly inaccessible. They are off limits to the public. A mystique ... envelops the islands, and it is well earned. These islands -- Gardiners, Great Gull, Little Gull, Plum and Robins -- have been the setting of some of Long Island's most exciting historical chapters. Captain Kidd buried pirate treasure there. One Island woman was tried for witchcraft decades before Salem's trials. Another was so beautiful that she dazzled Washington society [and] married the President. And during the cold war, one island was used for secret research for a germ warfare attack on the Soviet Union. Plum Island ... is strictly controlled and it has the tightest security of all the islands. Unlike the secret germ warfare project in the 1950's, the first Federal project on Plum Island was quite open and ordinary. In 1826, the Government belatedly bought 3 of its 800 acres for a lighthouse. About the time of the Spanish-American War, the Government bought the rest of Plum and built Fort Terry as the headquarters for artillery batteries at Montauk. Federal officials ... converted the site to the Animal Disease Center in 1954. Since 1929, the country's only outbreak of the dreaded foot-and-mouth disease was in 1978, when it spread to animals outside the laboratory buildings. For decades, officials denied rumors of biological warfare experiments. But in 1993, Newsday unearthed previously classified documents on plans to disrupt the Soviet economy by spreading diseases to kill its pigs, cattle and horses.