For U.S. Lt. Col. Christopher Giaimo, alone in a Havana hotel, the knock on the door came just after dawn.

Bodyguards with AK47 rifles ordered him downstairs and, without explanation, drove him two hours across Cuba. They put him on a helicopter and flew him to a tiny island, across from the Bay of Pigs.

Only when he landed there did the Air Force officer realize Fidel Castro had summoned him as a gesture of hospitality.

"He was sweating those little beads of sweat all over him," said Rep. Bill Alexander (D-Ark.), who was with Castro on Stone Key. "He said, 'God, I thought they were taking me to prison.' "

Giaimo, who works in a congressional liaison office in the Pentagon, declined to discuss the incident, apparently still seeing little humor in his three-hour scare. But he said through a spokesman that he would not quarrel with the facts of the story as told by Alexander and Castro himself.

Giaimo was in Cuba as an escort officer for Alexander and Rep. Jim Leach (R-Iowa), a service the military frequently provides for traveling members of Congress. When Castro invited the congressmen on a fishing excursion to the southern coast, Alexander decided to leave the officer behind.

"We decided not to take the colonel, because we wanted to engage in open talks and sensitive talks, which it turned out they were," the congressman said.

But Castro later told Washington Post editors in an interview that he noticed immediately that the U.S. party was short one member.

"Can I ask where's the colonel?" he recalled saying. "I said, 'Why didn't you bring the colonel? Why should we feel that the colonel is going to invade this key?' "

According to Alexander, Castro declared, "There's nothing to hide. Summon the colonel."

So early the next morning the colonel, who does not speak Spanish, was called and told, apparently in halting English, to pack his bags. Fifteen minutes later the guards appeared, instructed him to forget his bags and escorted him out. "He was sweating those little beads of sweat all over him. He said, 'God, I thought they were taking me to prison.' " -- Rep. Bill Alexander, above

"They drove him out of town," Castro said. "They drove him on a highway, for one hour and fifty minutes. They put him on a helicopter. He flew over the sea and then they landed him on a key. And the way he tells it, no one told him where he was going.

"I think he was joking when he said that," Castro concluded.

Not so, said Alexander. Lt. Col. Giaimo did not see the joke.