He left the yellow dorid to its feasting and continued on. Having found one nudibranch, he now saw that the rocks were speckled with them. Some were identical to the first, but there were others as well: the ghostly white Discodoris, phantom of the reefs; Dialula sandie-gensis, spotted black like an undersea cow; tiny orange Rostanga. The various species existed side by side, each concerned only with locating and consuming its particular food source, few of which were shared. Ben had once counted seventeen distinct species on the reef in a single dive. It was believed that the waters of Whaler’s Cove were home to more than thirty.

Among them, there was one with which Ben was enamored more than the others. He looked for it now. Unlike its kin, it was seldom so public in its appearances, preferring to remain tucked into less accessible places like a camera-shy starlet. Like Garbo. He had never seen one roaming freely on a rock; always they were discretely situated. But over time he had developed a knack for finding them, primarily by blocking out all other images from his mind so that only the one he sought registered on his vision.

It took him fifteen minutes of searching, and several false starts, before he located what he was after. When he found it, it was not on the rock but affixed to a piece of kelp that had somehow been removed from its stalk and now lay on the sandy bottom like a discarded length of ribbon. The nudibranch was moving across it, a bright spot of white against the dark green background. Having found its preferred food in the form of a scalelike sponge that barnacled the kelp leaf in dime-sized patches, it was in no hurry to go elsewhere.

Less than an inch in length, the animal was milky in color, almost translucent; Ben could see the green of the kelp beneath it through the nudibranch’s outer edges. The perimeter was lined in startling yellow, and a row of similarly colored spots ringed the creature’s body. Its rhinophores, the hornlike structures at its anterior end, were pure black.

Cadlina flavomaculata—the yellow-spotted Cadlina—although in its case he broke from his preference for accurate scientific nomenclature and called it Devil Horns, a name of his own invention. It was his favorite, for reasons he found difficult to put into words. True, it was the first species he had found on his own, without a more experienced diver to point it out. But something about it enchanted him, its ethereal appearance and incongruous assemblage of multicolored parts. Perhaps its reticence to be observed.

Cadlina. Caddie. His joy faltered at the thought. Caddie. His daughter. Soon to arrive back in his life. He’d gone beneath the water to escape his fears over her imminent arrival. He realized now that it was a futile effort. How could he possibly forget the child named for the object of his fascination?

A shadow, larger than usual, floated slowly across the kelp leaf, eclipsing the tiny moon of the nudibranch. Turning his head, Ben looked up in time to watch as a leopard shark, its belly a pale, luminous silver, passed a dozen feet above him. Although not at all uncommon to the waters of Monterey, a sighting of the shark was not something to pass off as an everyday occurrence. The creatures were timid, easily startled, and particularly leery of the bubbles produced by divers.