Then an opening appeared on the starboard side of the vehicle’s flat hull. Cédric would never know whether the hatch, lid, panel, or whatever it was had recessed into the hull or sprung inward like a trap door—it happened too quickly for him to tell. The opening appeared. And before he could react, a compartment behind the opening released its implausible contents into the water.

The twenty or so dispersing spheres looked to him like metal ball bearings, although they were somewhat larger than racquetballs in size. Each of them had four tiny screw propellers—one on the upper axis, one on the lower, another two on opposite points across its diameter.

His eyes wide with amazement, Cédric thought crazily of a toy called a Pokéball he’d once gotten his youngest nephew for his birthday, something that opened up like an egg to release a little cartoon imp.

He was still thinking of it when the spheres assembled into tight cluster formation and came swarming toward the spot where he stood with his dive partner.

“Cédric . . . what’s going on?” Tension brimmed in Marius’s voice. “What are those things?”

Cédric couldn’t waste an instant with guesswork. He switched to the diver-to-surface freq.

“Africana, we have a situation,” he said.

He got an earful of silence in response.

“This is a mayday, Africana. Repeat, mayday, can you read?” he said.

More dead silence from topside.

“God damn it, come in, what’s wrong with you up there?”

Still nothing. And the rapidly moving spheres were almost on them.

Cédric abandoned the radio, looked at Marius. He had no shred of a plan in his head, and the knowledge that their thrusters weren’t designed for speed hardly inspired confidence one would come to him. But Cédric had been a navy man for a very long time, and he did not like it at all that the lens-shaped aperture and black projection on the minisub were reminiscent of the guidance and homing packets of seeker torpedoes.

The robotic swarm meant danger.

“We have to get away,” he said. The declaration sounded blandly, hatefully obvious. “Try to—”

They were the last words he managed to get out of his mouth before the spheres came swooping down on them.

He felt three quick, clapping thumps on the back of his thruster unit, a fourth against the POD encasing his right hand, followed by a fifth and sixth on his left. There were some hard claps to his chest and the side of his neck, and the next instant a staggering thump-thump-thump against his foot that almost threw Cédric off balance into the muddy sediment.

“My God!” Marius shouted over the comlink. “They’re sticking to us. Sticking!”