Just as Dante’s glove closed over the cartridge, the grotesque head of a moray eel exploded out of the hole, revealing an improbably gaping mouth of inch-long needles. Shocked, he snapped back his arm, and the jaws bit down on the metal of the marker buoy, sending broken teeth in all directions.

In a panic, Dante dropped the cartridge and reached for the valve of his B.C. Star grabbed him before he could inflate the vest and shoot upward.

he pushed her mask right up against his, communicating her message with dark eyes: Calm down. It didn’t happen. You’re okay.

Dante nodded, gasping into his regulator. He was a pretty crummy diver, Star reflected, but sometimes luck was more important than skill. The big eel could have taken a substantial chunk of flesh out of his hand.

Not far away, Kaz and Adriana were tagging a cave entrance with another one of the marker buoys. There was a pop followed by a hiss, and the float rocketed to the surface.

One down and five hundred to go, Star thought to herself. She still couldn’t figure out why Tad Cutter needed this. To map every grotto and nook in a reef system the size of Hidden Shoals would take years, not a couple of months. It didn’t make sense.

he was enjoying the chance to dive without the bulky scuba tank. It was a feeling of freedom, although she was tethered to the Brownie by her air hose and safety line. Soaring and swooping with the fish, pretending to be one of them – it was a childish game, but Star never got tired of it.

he swam with a school of mackerel until they were scattered by a big loggerhead turtle. The loggerhead’s stony shell felt ancient against her gloved hand – a piece of prehistory here in the twenty-first century.

he spotted Kaz hovering over another cave, unclipping a fresh marker buoy from his belt. He wasn’t much of a diver either, she reflected. But there was an ease, almost a grace to his movements – something only natural athletes had.

As Star watched him work, a large barracuda loomed up behind the boy.

Should I signal him?

he remembered the incident with the shark. Kaz was easily spooked, and might do something stupid. Besides, barracudas never attack humans on purpose.

But the seven-footer was nosy. Star bit her tongue as the protruding lower jaw probed right up behind Kaz, the gleaming teeth mere inches from the back of his neck.

All at once, Kaz turned around, coming face to jaws with the notorious predator. Shocked, he triggered the marker buoy. The pop startled the barracuda, and it turned tail and darted away. Star laughed, sending clouds of bubbles rushing for the surface.

Adriana was nearby, paralleling the bottom, trying to shoo away an aggressive lobster. She was a little more comfortable in the water than Kaz – a tourist, rather than a beginner. The girl was obviously rich and had done some diving on high-priced vacations in the past.

It bugged her. Not that Adriana was loaded, but that Poseidon had matched Star with such unqualified teammates.

Then again, how could they be sure I was any good? They knew about my cerebral palsy …

It was almost as if Poseidon had gone after weak divers on purpose.

“Look!” came a cry.

Dante again. If the boy didn’t stop yelling underwater, he was going to drink enough salt to give himself high blood pressure.

He was pointing and waving – probably at another rabbit hole he considered a cave. But when she swam to his side, he was gazing off into the distance, where the reef fell off into deeper water.

he squinted, trying to zoom in on the object of his interest. Light, and therefore visibility, diminished with depth. She shot him an expansive shrug. Because of the need to communicate without words, divers often used exaggerated gestures like stage actors playing to the back row.

Dante deflated his B.C., descending into the twilight. Star followed. A tug at her belt told her that the safety line had become taut, and that they were now pulling the Brownie along with them. She glanced over her shoulder and saw that the others had noticed it too. Kaz and Adriana finned after them.

What does Dante think he sees? There was such a thing as an underwater mirage. His magnified eyes behind his mask gave him a deranged appearance. It was easy to believe he was hallucinating.

And then she spotted it.

In the middle of this most natural of settings, it was jarring to see something so artificial, so manmade. The sunken airplane sat in the sand, its fuselage partially encrusted with coral and sea life. One wing had broken off on impact with the water. It lay a short distance away, hidden by seaweed.

tar’s heart began to pound so hard she was afraid it might burst her wetsuit. This was the ultimate diver’s prize. A wreck! She had read about this experience in scuba magazines. But the excitement of the real thing went far beyond anything she could have imagined.

he approached slowly, reverently, half expecting the plane to vanish just as she reached out to touch it. Never had she imagined this could happen to her – and certainly not when she was teamed up with a bunch of landlubbers like this bunch! The others hung back, watching her uncertainly.

When she spotted the insignia on the side, a gasp escaped her – a larger bubble among the many smaller ones. The marking was obscured by anemone growth, but it was unmistakable. A swastika! This was a German warplane from World War Two!

he swam over to peer into the cockpit, half expecting to see a skeleton at the controls. But, no. The big bomber was deserted.

The windshield was shattered, providing a narrow entryway to the downed plane.

tar hesitated. Wreck diving could be dangerous.

But this is the chance of a lifetime!

he entered the cockpit and squeezed between the pilot’s and co-pilot’s chairs into the body of the plane. The space was tiny – it was hard to believe that an entire crew of grown men flew in this cigar box. Just a few feet into the fuselage and she was in near total darkness. The only light was from two turrets of bulletproof glass. Out of each pointed a swiveling machine gun, harmless now, encased in a layer of coral. It was a grim reminder that this silent metal husk was once an instrument of war, a delivery system for death.

he snaked back toward the bomber’s tail. Here, there was absolute blackness, and the walls closed in until she was in the narrowest of tunnels.

As she reversed course, her flipper caught on the low ceiling and came off. Alertly, she was able to trap it between her legs. Putting it on again in the cramped space was a major operation, and she was surprised at how exhausted it left her. Her bubbles, trapped below the ceiling of the craft, converged to form a small pocket of air.

I’d better get out of here.

But not without a souvenir – some kind of proof that she’d been there. Artifacts, the wreck divers called them. Plates and silverware from sunken ships were especially prized. But what to take from a plane? She couldn’t exactly snap off a three-hundred-pound propeller.

Once again, her eyes fell on the machine gun. A full strap of ammunition dangled from the carbine, waving lightly in the current.

he crawled rather than swam up to it, grasping holds on the floor of the cabin. Popping the shells out was easier than she expected – the old strapping fell apart on contact, and the bullets dropped into her glove. The thrill of their touch was almost tangible.

World War Two in the palm of your hand, she reflected. Hey –

Fiddling with the gun had disturbed the layer of silt that covered the plane. A storm of swirling brown particles filled the turret. The bullets slipped through her fingers and disappeared.

Going after her prize was instinct. Any diver would have done the same thing. She ducked into the cloud as if bobbing for apples. That was when she felt it – no flow of compressed gas from the demand regulator between her teeth.

he was out of air.