Samantha and Nipper had no formal martial arts training, but they had almost ten thousand hours of pillow-fighting experience between them. They had no idea why they were under attack, but they were not going down without a fight.

As the man drew close, they could see that he was indeed some kind of ninja. At least, he was dressed like one. He wore a black hood that covered his entire face, except for the narrowest slit where his eyes peeked through. He had on a long black coat and baggy black pants that drew tight around his shins, revealing black socks and black split-toe ninja slippers.

And he was smeared with garbage. Or that was what it looked like. Brown and green splotches covered his shirt and coat. A yellowish stripe ran down his left thigh. It looked like a bird had recently pooped on his right shoulder.

He moved swiftly and silently, but his smell screamed out loudly. In seconds, he was within a few feet of the kids. Then he stopped.

“How did you get that umbrella?” he demanded. “There are twenty ninjas in the United States right now, looking for—”

Nipper sprang forward. He moved quickly and maneuvered himself directly behind the shrouded man. Then, holding tight to his loaf of bread, he swung at the ninja’s back with all his might.

There was a loud thwack. The bread struck something flat and hard beneath the ninja’s shirt. It felt to Nipper almost like he’d hit a plank of wood.

In a flash, the ninja turned, drawing a long silver sword from a sheath at his side. Even faster than Nipper had launched himself, the ninja diced the bread into tiny cubes that dropped to the sidewalk. Before Nipper could react, the ninja raised one of his smelly feet and kicked him in the center of his chest, knocking him backward onto the bread cube–sprinkled pavement.

Samantha stepped between Nipper and their attacker. Defiantly, she held up the throwing star–studded baguette in one hand. In the other, she grasped the metal tip of the umbrella and pointed the wooden handle at him.

“I’ve heard that Parisians aren’t friendly to visitors,” she said. “But this is ridiculous.”

“Yeah,” said Nipper, scrambling back to his feet. “France isn’t making a good first impression.”

“I don’t care about France,” the ninja muttered. His accent might have been British. It was hard to tell, as it was coming through the filthy face mask. It clearly wasn’t a French accent. He shifted his body, adjusting whatever it was that he was concealing inside his shirt. Then he lifted his sword and waved it at Samantha. “Hand it over,” he told her.

“You don’t want this bread,” said Samantha. “It’s stale. And it’s full of metal blades.”

“No!” said the man in black, much louder. “The umbrella.”

“You forgot to say s’il vous plaît,” said Samantha.

“I don’t speak French,” said the ninja. “Now let me have it.”

Samantha was happy to let him have it. She gathered her strength and brought the umbrella down on his head as hard as she could.

Wham! The man let go of his sword and fell face-first onto the pavement, knocked out cold.

Nipper bent down and rapped his knuckles on the center of the unconscious ninja’s back. It was like knocking on a door. He started to reach for the ninja’s sword, but Samantha grabbed his shoulder.

“Leave it,” she said. “The handle’s gross and sticky, and we’ve got to get out of here now.”

Nipper looked back at the grimy man and his grimy weapon and nodded in agreement. Then he and his sister ran.

They retraced their path along the sidewalk and through the break in the stone wall and headed into the crowded Louvre plaza. They pushed their way through the tourists, searching for the spot on the ground where they’d emerged. Just as they were about to reach the huge glass pyramid, they stopped short. Two ninjas stood, side by side, in their path, and it looked like they were on the very tile that had lifted Samantha and her brother from the magtrain chamber. The two black-clad figures didn’t notice the kids. They were busy studying the tile beneath their feet. They knew it wasn’t just an ordinary part of the plaza. They were clearly trying to figure out how to make it do something.

“They found the square,” said Nipper. “But I don’t think they know about the secret stomp.”

Samantha glanced sideways to make sure that she still had the umbrella on her shoulder. Then she grabbed her brother’s hand and they ran through the crowd and away from the Louvre. They turned to their right and ran to the closest point of the low stone wall that surrounded the plaza. They hopped over it and sat down on the grass, out of sight.

“I think I saw another way out of here,” Samantha said, catching her breath.

She popped open the umbrella and Nipper handed her the magnifying glass.

“Right here,” she said, pointing at the drawing of the Eiffel Tower centered in the lens. “I think there’s some kind of connection from here to Italy.”

There was a tiny arrow beside the lowest landing of the Eiffel Tower, just above the arch that forms the legs. Above the arrow, tiny dots were arranged in a cluster that looked like the letter R. A line started there and ran halfway across the umbrella. Unlike the dotted magtrain line that ran from Seattle to France, this line was a chain of little spirals. It looked to Samantha like a gust of wind.

The line ended at a picture that was definitely the boot-shaped country, Italy.

“There must be a lot of ways to get around using the Plans,” Samantha said. “Now let’s go find that boot—I mean, those dots,” she said. “Or that letter R. Or an arrow, or, um—”

“I get it, Sam,” Nipper cut her off. “Let’s go check out the tower.”

They hopped back over the wall and quickly headed away from the plaza. They ran down a narrow street lined with restaurants and small hotels and didn’t stop until they came to a gloomy-looking woman standing next to a table and chairs outside a café.

Samantha had remembered that the Eiffel Tower was Paris’s tallest building, so she was ready with the second thing Uncle Paul had taught her to say in French: “Where is the tallest building in Paris?”

“Où se trouve le plus grand édifice de Paris?” she asked.

The woman’s expression brightened instantly. “La Tour Eiffel!” she exclaimed, and pointed down the street. She gestured with a curved hand to show that they should follow the bend in the road ahead.

Samantha said, “Merci.” That was the third and final thing she knew how to say in French.

She and Nipper ran down the street, and as they rounded the curve, they saw the banks of the river Seine. Off in the distance, the Eiffel Tower came into view.