Magic comes to the Irish donkey, Barley Mars, through the English girl, Lynda. But when the donkey herd disown him and Lynda rejects him, Barley finds another, more sinister magical power. One which throws the quiet seaside village of Dundreeda into uproar.
Breadeye, streetwise full, leader of the Dundreeda seabirds, seizes his golden opportunity to treble the trouble. No-one escapes Breadeye's tyranny...not Paddy, the guillible sheepdog, the seabirds, the donkey herd nor, of course, Barley himself.
Unwittingly, Breadeye helps Barley towards the secret he needs to save Lynda's life. But this strange gift has a downside. To his horror, Barley finds the dolphins expect far more of him than is possible even for a magic animal.
Carnival time in Dundreeda is disrupted by a near environmental disaster, in which Breadeye, too, comes out a loser. Temporarily. This gull's resorcefulness knows no limits.
Together, Lynda and Barley reveal the mystery behind the Sea Monster and the stolen gun. But Breadeye leaves Lynda with one mystery she never quite manages to solve.