Bob Boyd is an independant geologist who came to Fort Farell to work for the Matterson corporation.  He should study a piece of land where this Matterson company plans to build a dam.  It would be just another job for just another employer, if Boyd wouldn't have bumped into the name Trinavant twice, a name that is strongly linked to his past.  Or rather, what he remembers of it, since he has no recollection of what happened to him before his accident - he's not even sure of who he is.

Long after he finished his job he returns to Fort Farell.  To his surprise the dam is being built despite what he found there, but when Howard Matterson immediately tries very hard to get him out of the village Boyd has other worries on his mind.  What caused this swift and hard reaction?  It can't be Boyd's friendship with Clare Trinavant, at least that can't be the whole explanation.  When the old Bull Matterson gets himself involved in the matter Boyd starts to sense that fear is the key, but what do they fear he might find?

The usual ingredients are here: an ordinary man being pushed in a less ordinary situation surprises himself and his surroundings.  The story is well-told and action-packed.  There's the usual bit of romance, a touch of humor, and a truckload of thorough documentation that is excellently dosed blended into the story - I mean, who else than Desmond Bagley can make a geology lesson actually sound exciting?  The first chapter gives you just enough to wonder where each bit will lead to, the second fills you in on Boyd's background, and from the third on Bagley takes you on an unstoppable ride to the finale, a ride you'll have a hard time interrupting.  As usual.