“It’s a way out!” Owen said, his heart gushing with relief. He observed that the door was about as high as the hole in the ceiling. They swam the short distance and discovered the staircase extended into the water. They were sopping wet and dripping, but that was no concern to them at all as they tromped up the stairs.

Before continuing, they stopped to examine the boat. It was a small canoe-shaped thing, big enough for maybe two adults. There was a pair of oars leaning upright in the interior. The wood was polished and well-worn.

Owen was wondering why a canoe was there, but then he saw that the cistern extended down quite a distance, probably underneath the entire length of the palace, which formed the roof of the cistern.

The Mortimer girl knelt by the canoe, rocking it slightly to see how sturdy it was before she followed Owen’s gaze across the shadowed waters.

“They keep this boat here so they can get to the other side without getting wet,” she said. “Come on, let’s check the door. I hope it isn’t locked.”

She grabbed his arm and pulled him up the stone steps. The water still rippled and lapped against the lower steps, disturbed by their plummet from above. The noises echoed eerily in the dark cistern, making Owen look back and stare into the blackness.

The door was narrow and wedged into a brace of stone. There was a handle and an intricate locking mechanism that was not operated by a key. The Mortimer girl tugged on the handle, but the door held firm. Owen recognized the lock as an Espion design, one that needed to be released from the outside. He pushed her hands away from the handle and quickly examined the mechanism. In moments, he figured out the triggering part and released the latch.

“How did you . . . ?” she stammered in amazement, staring at him with open admiration.

He shrugged and said nothing, not wanting to reveal anything Ankarette had taught him about the ways of the Espion. The door took some pulling to open and they saw a weave of ivy blocking the way, which explained why they hadn’t seen the door while they were in the courtyard beyond. The mouth of the cistern was not far away.

“I’m jumping again!” she declared, and rushed out the door. He followed her and then watched as she rushed up to the edge and made her jump. He could hear the squeal before the splash sounded below him.

Owen’s heart hammered with nervousness. He had done it once. He could do it on his own.

“Come on down!” she called to him. “I’m out of the way!”

He stared at the hole, pursed his lips, and then marched up to it. He stared down, his stomach wrenching violently as he stared down at the drop. There she was, paddling just outside the fringe of light in the shadowy waters, gazing up at him, her face beaming.

Owen counted in his heart. One. Two.

He stopped before thinking three and just jumped.

It was even more fun the second time, and he cut through the water like a knife, plunging through the depths. He went down all the way to the bottom until he felt the stone of the floor. Bubbles streamed up around him and he opened his eyes.

And he saw casks of glittering jewels and coins. Strange jeweled scabbards and ropes of pearls covered the floor of the cistern. There was a battered shield, with a huge gouge on its polished surface. None of the metal was rusted. He saw glass vials with stoppers. He kicked off the floor and rose to the surface, spluttering with shock.

“You did it!” the Mortimer girl beamed. “I knew you weren’t too scared. I want to jump again!” She started swimming toward the steps.

“Wait!” he said, half choking and spitting out some water. “There’s . . . there’s treasure!”

She turned midstroke and looked at him, confused. “What did you say?”

“Down at the bottom!” he said excitedly, paddling hard. “I saw it!”

She looked confused. “I can see the bottom, Owen. It’s just stone. Stop teasing.”

Owen stared down and could only see his reflection in the water. He plunged his head below the surface, blinking rapidly despite the pain in his eyes and the watery view. This time he saw nothing but stone and shadows.

He pulled his face up, dripping. “I saw something! I’m not teasing. When I jumped, I held my arms stiff and went all the way to the bottom. I opened my eyes and saw piles of treasure. There were swords!”

“Swords?” she asked in wonder. “Let me try it.” She swam to the steps and slogged up them, hiking up her skirts and pattering water like she was a raincloud. She marched back up to the door, which they had left ajar, and Owen moved away from the circle of light on the water. He wiped his face and waited for her shadow to appear above him.