Excerpt from Flashback by Nevada Barr, plus links to reviews, author biography & more

Chapter 1

Until she ran out of oxygen, Anna was willing to believe she was taking part in a PBS special. The water was so clear sunlight shone through as if the sea were but mountain air. Cloud shadows, stealthy and faintly magical at four fathoms, moved lazily across patches of sand that showed startlingly white against the dark, ragged coral. Fishes colored so brightly it seemed it must be a trick of the eye or the tail end of an altered state flitted, nibbled, explored and slept. Without moving, Anna could see a school of silver fish, tiny anchovies, synchronized, moving like polished chain mail in a glittering curtain. Four Blue Tangs, so blue her eyes ached with the joy of them, nosed along the edge of a screamingly purple sea fan bigger than a coffee table. A jewfish, six feet long and easily three hundred pounds, his blotchy hide mimicking the sun-dappled rock, pouting lower lip thick as Anna's wrist, lay without moving beneath an overhang of a coral-covered rock less than half his size, his wee fish brain assuring him he was hidden. Countless other fish, big and small, bright and dull, ever more delightful to Anna because she'd not named them and so robbed them of a modicum of their mystery, moved around her on their fishy business.

Air, and with it time, was running out. If she wished to live, she needed to breathe. Her lungs ached with that peculiar sensation of being full to bursting. Familiar desperation licked at the edges of her mind. One more kick, greetings to a spiny lobster (a creature whose body design was only possible in a weightless world), and, with a strong sense of being hounded from paradise, she swam for the surface, drove a foot or more into the air and breathed.

The sky was as blue as the eye-watering fishes and every bit as merciless as the sea. The ocean was calm. Even with her chin barely above the surface she could see for miles. There was remarkably little to soothe the eye between the unrelenting glare of sea and sky. To the north was Garden Key, a scrap of sand no more than thirteen acres in total and, at its highest point, a few meters above sea level. Covering the key, two of its sides spilling out into the water, was the most bizarre duty station at which she had served.

Fort Jefferson, a massive brick fortress, had been built on this last lick of America, the Dry Tortugas, seventy miles off Key West in the Gulf of Mexico. At the time construction started in 1846, it was the cutting edge of national defense. Made of brick and mortar with five bastions jutting out from the corners of a pentagon, it had been built as the first line of defense for the southern states, guarding an immense natural-and invisible-harbor; it was the only place for sixty miles where ships could sit out the hurricanes that menaced the Gulf and the southeastern seaboard or come under the protection of the fort's guns in time of war. Though real, the harbor was invisible because its breakwaters, a great broken ring of coral, were submerged.

Jefferson never fired a single shot in defense of its country. Time and substrata conspired against it. Before the third tier of the fort could be completed, the engineers noticed the weight of the massive structure was causing it to sink and stopped construction. Even unfinished it might have seen honorable--if not glamorous--duty, but the rifled cannon was invented, and the seven-to-fifteen-foot-thick brick-and-mortar walls were designed only to withstand old-style cannons. Under siege by these new weapons of war, the fort would not stand. Though destined for glorious battle, Jefferson sat out the Civil War as a union prison.

Till Anna had been assigned temporary duty at the Dry Tortugas, she'd not even heard of it. Now it was home.

For a moment she merely treaded water, head thrown back to let the sun seek out any epithelial cell it hadn't already destroyed over the last ten years. Just breathing--when the practice had recently been denied--was heaven. Somewhere she'd read that a meager seventeen percent of air pulled in by the lungs was actually used. Idly, she wondered if she could train her body to salvage the other eighty-three percent so she could remain underwater ten minutes at a stretch rather than two. Scuba gave one the time but, with the required gear, not the freedom. Anna preferred free diving. Three times she breathed deep, on the third she held it, upended and kicked again for bliss of the bottom.

Reprinted from Flashback by Nevada Barr by permission of G.P. Putnam's Sons, a member of Penguin Group (USA) Inc. Copyright (c) 2003, Nevada Barr. All rights reserved. This excerpt, or any parts thereof, may not be reproduced in any form without permission.