No nine-to-five cubicle career will suit Stacie Calder - the naturalist much prefers working in the great outdoors. Specifically, the spacious and spectacular Alaskan wilderness, whose rugged charms she shares with sightseers on the top deck of the tour boat where she works. But one May afternoon, Stacie's passengers see more than glittering glaciers, frolicking harbor seals, climbing bears and soaring seabirds...they also witness a man lying dead in the frigid Alaskan waters. And it seems likely that someone gave him a fatal push. Stacie is shaken to find herself on that suspect list.