“We don't expect to see anything like this until September, if then,” John said. “It's a rare year with this kind of activity.”

The boat flushed ten, twenty herring gulls, black-backed gulls, laughing gulls, roseate terns—all rising in a screeching, cawing white cloud of wings. Liam looked over the side, saw the silver ribbon of fish extending in all directions. John drove out toward Block Island, across the Sound. The silver fish swam in a stream, a river of small fish weaving out to sea. And the oceangoing birds followed them in—more gulls and terns than Liam could believe.

“Is that—?” he asked, pointing up.

“A northern gannet,” John said. “Spends most of its life at sea.”

“Yet it's here in Block Island Sound?”

John's lips tightened. Liam knew that he had to be thinking the same thing—if these quantities of bait could pull in a northern gannet flying above the surface, what species of fish might there be swimming beneath? Liam thought of Nanny—whose whereabouts had been unknown these last days—and shivered.

A flotilla of motorboats—Boston Whalers, Grady-Whites, Aquasports—and Jet Skis towing surfers on surfboards passed by. Liam's attention was captured by another boat—a dark green trawler with a familiar low profile. Raising the binocs to his eyes, he felt his blood run cold. The ship was Mar IV, with its home port of Cape Hawk emblazoned in gold on the transom. There was its captain, Gerard Lafarge, standing at the bridge.

“A friend of yours?” John asked.

“Hardly,” Liam said. “He's a fisherman I know from home. We've had a few run-ins, with him catching dolphins and selling them as tuna.”

“We'll turn him in,” John said, reaching for the radio transmitter. “If he's Canadian, he's not supposed to be fishing in Rhode Island.”

“He's not fishing,” Liam said, staring through the glasses. Lafarge was standing still, gazing at the waves. His outriggers were pulled in; the nets were rolled tight, the trawl doors up and inactive.

“So what's he doing here?” John said.

“That's what I'd like to know,” Liam said as Mar IV steamed toward the action with the rest of the boats.

Just ahead, the giants were rising to life: Ghost Hills. Liam felt the water temperature rise—these ocean waves were straight off the Gulf Stream, brilliant cerulean blue, clear as sunshine. They rose fifty feet into the air, wild and thunderous, sliding over the reef, enormous and unbroken, then exploding into white foam.

“What are they?” Rose asked, sounding amazed.

“The biggest waves we've ever seen,” Liam said, his arm around her.

“In the middle of the sea? I thought waves only broke on the beach,” she said.

“They're breaking on an undersea reef,” John said. “It only happens once or twice a century—when the wind and currents and tides are right.”