Six years have passed since Jamie Waterman took charge of a foundering expedition and courageously led its surviving members to perhaps the greatest scientific discovery in the history of humankind: extraterrestrial life in its most basic form. But things have soured for Waterman back in Earth's rich atmosphere since the monumental breakthrough that brought him fame and-for a time-happiness. Now a second Martian expedition has been announced. Jamie Waterman is named commander and must journey back to the eerie, unforgiving landscape of towering cliffs and sere natural beauty that haunts him still. But a destructive rivalry, a new emotional attraction, and a series of deadly unexplainable ''accidents'' could doom the mission of which he is in charge. Yet Waterman knows he must not fail. For there are still great secrets to be uncovered on this cruel and enigmatic world-not the least being something he glimpsed in the far distance during his first Martian excursion; an improbable structure perched high in the planet's carmine cliffs: a dwelling that only an intelligent being could have built.