“We’re sightseeing,” Jupiter said. “Prince Djaro has asked us to help him recover the royal spider of Varania. It has been stolen and a substitute left in its place.”

“Uh-oh!” Bert Young exclaimed. “That’s worse than I thought. Can you help him?”

“I don’t see how,” Jupe admitted.

“Neither do I,” Bert Young agreed. “But stay with it and keep your eyes open. Anything else?”

“We’re in the park and we’ve probably been followed. We don’t know by whom.”

“Try to get a look at them. Report back to me later, but wait until you’re alone. Someone may get suspicious if you talk now.”

With that Bert Young broke off. Jupiter took his pictures, while Bob looked slowly all around. Seeing nothing — that is, no one who looked like he was shadowing them — he dropped some American coins into a clown’s basket.

Now the clowns led out a French poodle, who did somersaults and stood on his front legs. The crowd gathered around to watch, leaving the balloon girl free for the moment.

“Now we take a picture of the girl,” Jupiter murmured to the others. They all moved over, Jupiter focusing his camera. The girl saw him, smiled, and posed. Jupiter snapped the picture. Then the girl came forward with her balloons.

“Buy a balloon, young American gentlemen?” she said. “Set it free, let it soar into the clouds and take your wish up to heaven.”

Pete found some American money and gave it to her. She handed each of them a balloon and then turned to the task of making change. As she bent over the coins, she whispered beneath her breath.

“You are being followed. A man and a woman. They do not look dangerous. I think they want to talk to you. Sit down at a table over there and order ice cream. Give them a chance to talk to you.”

The boys each made a wish and released their balloons. They watched them till they were tiny dots in the sky. Then they strolled over to a space where a number of tables with checkered red cloths stood on the grass. They sat down at one and a waiter with a handlebar mustache hurried over and said, “Ice cream? Maybe hot chocolate? Sandwiches?”