This first volume of a fictional epic tale scattered with Basque mythological reference Joanes, the protagonist, tries to make his fortune as a whaler during an era when the whales in the Bay of Biscay were becoming scarce.  Forced to look farther afield, but without the means to do so. 

Here is when the story begins to depart from historical fact and the narrative weaves in elements of Basque Legend.  With the help of witches Joanes summons a sea-devil who assist him...But for a price!  

The book ends with whatever possible danger hangs over the recent sucess of Joanes (and his crew) as he has to live up to his unhallowed pact.