treasure,” he added enthusiastically.

Like most boys his age, Ian loved the idea of exploration and hidden treasure. He often fantasized about discovering some gem or historical relic within one of the many tunnels he and Theo explored. His dream was to find something of value so that he could sell it and use the proceeds to help secure his and Theo’s futures once they left the orphanage. At the very least he considered these underground jaunts to be good training for the day when he became a real explorer, traveling the globe in search of lost civilizations and hidden treasure. This had been Ian’s life’s ambition since he was seven and read the book Treasure Island.

To that end, he and Theo had spent many happy hours belowground, tracing the steps of villagers and warriors from the Middle Ages who had first dug out and even lived in the chalky space under the earth.

Most of the tunnels wound their way through the top part of the cliffs. Some led to caves that opened up to the strait; others led all the way into Castle Dover, through the host of secret entrances in the mighty structure. Still others came to a dead end and offered little in the way of entertainment.

As Ian walked, he traced on his map some of the branches of tunnels he’d already explored. Theo caught up to him and looked over his elbow. “This tunnel,” he said, pointing to one particularly broad vein. “We never did go down the south fork of that one. I bet there’s a secret outlet, and I bet it’s somewhere close to here.”

“You’ve always had a knack for ferreting out secret entrances,” she said. “So I’ll go along with that.”

The pair continued to walk, and Ian used a staff he’d crafted to poke holes in the soft earth. They were not far from the edge of the cliffs, and the wind swirled the grass around them. Luckily, it was a lovely, warm day, so the wind didn’t bite as it usually did when they were this close to the sea.

While Ian paused again to get his bearings, Theo looked southeast across the strait and said, “Look, Ian. We can see clear to Calais.”

Ian glanced up at the French city, which was just visible. “Yeah, no fog or mist to get in the way today.”

“Someday I’d like to go to France,” she said wistfully.

Ian laughed. “Good ol’ Theo. Always wanting to be someplace other than where she is.” But just as he turned to smile at his sister, Ian’s staff pushed right through the scrub and slipped out of his hand, disappearing under the grass. He heard it clank a moment later. “Theo!” he said excitedly as he knelt down and began to pull at the scrub. “I think we’ve got something!”

Theo came to crouch beside him as he tore at the place where his staff had disappeared, and sure enough a hole barely half a meter wide opened up in the ground before them. “Here’s the torch,” Theo said, handing Ian the flash-light so that he could look inside.

Ian leaned down and pushed his arm and his head into the hole to shine the light about. Quickly, he pulled them out and with a brilliant smile announced, “We’ve hit the jackpot!”

“Another tunnel?”

“Yes!” he said. “And you wouldn’t believe the size of it! There’s plenty of room once we widen this hole. Come on, help me find a rock and we’ll get to work.”

The pair found some stones and began to pound out a larger hole. The rock underneath the scrub was made of white lime—chalk—and was extremely soft. In no time they’d managed to widen the hole enough for Ian to squirm through. “You’ll have an easy time of it, at least,” he said, looking at his much smaller companion.

Theo smiled brightly at him and moved to the entrance. “I’ll go first,” she said. “That way I can pull you in if you get stuck.”

Before Ian could stop her, Theo had slipped easily down into the tunnel. He poked his head in after her, and as he handed over the torch, he said, “Next time let me go first to make sure it’s safe, all right?”

She rolled her eyes. “It’s perfectly safe. Now come on. We’re wasting time.”

Ian pulled his head out of the hole and had a moment of uncertainty about whether to go in headfirst or feetfirst, but he finally decided headfirst might be best. The hole wasn’t quite as wide