Jack pursed his lips to whistle, but no sound came. He felt his gut give a little kick. “Yeah, maybe.”

Vincent sat forward. “Could a prop do that? A big freighter, with a twenty-five foot screw on full rotation?”

Jack knew it couldn’t make a wound that clean, no matter how sharp, or how fast the propeller was turning. “Maybe.” He handed the picture to Cate, whose brows were drawn together.

“Two maybes.” Vincent sighed and handed Jack his last photo. “Then there’s this, Mr Maybe.”

The image showed Vincent once again on the whale carcass. The picture was taken with some sort of 3D illuminating film that made much of the whale seem to float in space. But it was the huge torpedo-shaped shadow passing underneath the carcass that sent a jolt through Jack’s body.

He swallowed dryly. He knew exactly what it was. He went to hand it back, but Cate caught his arm, dragging the picture towards her.

Cate squinted hard at the image, and then straightened, her eyes dead as she handed it over. Jack felt her turn to him, but he wouldn’t look at her for fear of betraying his own thoughts.

“Well, Jack, you’re the expert. But tell me that doesn’t look like a shark.” Vincent sat back. “And yes, I know water can magnify some objects just below the surface, but the refraction and distortion rate is only in the order of about ten per cent.” He exhaled. “That damn thing looks to be sixty feet.”

“I also took some thermal shots. It was no whale, but it flared hot.” Regina’s green eyes were like gun barrels.

Jack nodded. “The Great White is warm-blooded, so it can regulate its own body temperature. That’s why it can adapt to different water temperatures. It’d be as hot as a whale.”

“A Great White; that’s what I originally thought.” Vincent reached into his pocket and pulled out the tooth fragment. He held it out. “From the bite wound.”

Jack took it in his palm, feeling its weight. It was a glossy white, around two and half inches long. He knew the largest Great White tooth ever found, measured out at about three inches. That was estimated to be from a shark around twenty-five feet in length. He looked at the blunt end – broken off – it had been bigger.

“Now that’s a goddamned big shark,” Vincent said.

Jack held it up. “Carcharodo…”

“Carcharodon Carcharias – yeah, that’s it… the Great White. Now I remember.” Vincent turned to Regina. “Thought so.”

Jack stared. “No, it’s something else.”

“Shit.” Cate stood up too quickly, knocking her chair over, and walking away.

Jack turned to her, reaching out to grab her forearm. She looked pale. He held on, looking up at her. “It can’t possibly be…”