Sarah laid her cheek against the cold glass of the porthole, extinguishing her own reflection. The water outside was only swirling darkness. No; there was light, an infinity of tiny gleams, suspended peat particles both refracting and swallowing the halogen searchlights of the submersible.

Sarah wondered once again why she had let Mark talk her into joining him on this run. The water was cold and dark and deep. Loch Ness, it was said, never gave up its dead.

She turned away from the window, inhaling deeply to reassure herself. But the air was stale. Sweat ran in tickling streams down her back.

Mark sat at the controls, humming delightedly to himself. Hydrophone, speakers cleared of static and echoing with the hollowness of deep water. Sonar transponder, steady lines on the oscilloscope, registering only fixed objects--the camera rig at the end of the pier and a couple of sunken logs.

He loved this, Sarah thought with exasperated affection. Electronic senses extended, circuits opening and closing at his command. No wonder he'd given up his summer vacation to take the job with the Expedition. It was his summer vacation. His yearly fix of marine biology spiking his day to day expertise in electronics. And I can work anywhere, in my mind or out of it.

Of course, the doctor said she was fully recovered, ready for a change of scene. Therapy for a nervous breakdown, or nervous hyper-excitement, or however coolly they defined that shadow lurking among her thoughts. They had defined the horror that had sucked Julie's life as cancer.

Sarah realized that her damp palms had left grey smudges along the edge of her sketch pad. The first page, mountains. The second page, cottages along the road to Inverness. The third page--nothing. Nothing here but darkness.

In the ravaged husk of Julie's body only her eyes remembered youth, staring in a dumb, anguished betrayal from the thicket of plastic tubes and leads and hoses that tied her down like a technological sacrifice.

The speaker clicked. Mark leaped to his deals, adjusting them as delicately as he had been touching Sarah since her sister's death. The speaker clicked twice more. "Listen," he said over his shoulder. "There it is again, just like yesterday. No known reason for those clicks. Don thinks that it might be some kind of sonar signal emitted by the animal."

The animal. The mythic monster. Estimated to be twenty feet long. Coasting silently through the darkness, through the cold darkness, attracted to the dim yellow shape and the muted lights of the submersible.

The submersible was about the same size as one of the beasts. Sarah's fingers tightened on her pencil and it broke. Sixty feet of thick water lay between her and the surface; this was the animal's element. Something hovered just beyond the circle of light, sensing their passage. She inhaled again, but her breath stuck in her throat and she choked. The sweat was cold now, flowing in streams down her face and body. Perhaps the sub was leaking, perhaps the seams had broken open.