It is the story of Tegla, an Old Welsh longshoreman, who determines to kill a grey seal which is spoiling his fishing and ruining his nets. He makes this decision at the same time Edward Drey, foolish, bumbling, slyly lustful, decides to seduce Tegla’s pretty young daughter Bronwen whom he sees bathing one day as he - ostensibly bird watching - scans the coast through his binoculars. The people who are subsequently involved have their lives influenced, in one way or another, by the seal: Drey’s unhappy wife Agnes; her lover Tony, who is not as slick as he appears; Caradoc, a nationalist and a harpist, who worships Bronwen awkwardly and tongue-tied, from afar.
After some superbly comic scenes, Tegla’s conflict is resolved in a moving and unexpected climax which combines comedy with pathos. The whole novel evinces a deep knowledge of wild life and a sharp eye for situation and character.