“I checked the system last night before I went to bed. The only unusual thing SOSUS had located was what we call a ‘dead zone,’ an area devoid of marine life. This in itself isn’t that unusual. The Gulf experiences annual dead zones every summer when plankton blooms created by fertilizer runoff deprive the water of oxygen. But those dead zones usually occur off the coast of Texas and Louisiana, and never in water this deep. Anyway, I reprogrammed SOSUS to concentrate on this area and left the system on search mode all night. The alarm went off about fifteen minutes ago.” Iz removes the headphones and hands them to her. “Listen to this.”

She hears static, like the zapping sound a fluorescent tube makes before it shorts out. “Sounds like white noise.”

“That’s what I said. Keep listening.” Iz changes the setting to a higher frequency.

The white noise disappears. Now Dominique hears an incessant, metallic thumping sound. “Wow. It sounds like hydraulics.”

Iz nods. “Ask your mother, I said the same thing. In fact, I thought SOSUS had picked up a submarine resting on the bottom. Then I rechecked the location.” Iz hands her a computer printout. “The acoustics aren’t coming from the seafloor, they’re coming from below the seafloor. Four thousand, six hundred and eighty feet below the seafloor, to be exact.”

Dominique’s heart is thumping like a kettledrum. “But how’s that possible—”

“You tell me! What am I listening to, Dominique? Is this a joke, because if it is—”

“Iz, stop talking nonsense.” Edie places a reassuring arm around Dominique’s waist. “Dom had no idea what you’d find. The information was given to her by, well, by a friend.”

“Who’s this friend? I want to meet him.”

Dominique rubs the sleep from her eyes. “You can’t.”

“Why not? Ead, what’s going on here?”

Dominique glances at Edie, who nods. “He’s—he’s a former patient of mine.”

Iz looks from Dominique to his wife, then back to Dominique. “Your friend’s a mental patient? Oy vey—”

“Iz, what difference does it make? Something’s out there, right? We need to investigate—”

“Slow down, kiddo. I can’t just contact the National Oceanic and Atmospheric Administration and tell them that I located hydraulic sounds originating a mile below the Campeche shelf. The first thing they’re going to want to know is how I discovered the acoustics in the first place. What am I supposed to tell them—that some looney-tune gave my daughter the coordinates from his cell in Miami.”

“Would it make a difference if Stephen Hawking gave you the coordinates?”