Soon Come

Ptolemy Turtle and his mother get a telegram saying that Daddy Turtle is coming home. An excited Ptolemy goes to the seashore to collect sea grapes for his daddy's favourite dessert and instead finds a baby mermaid. Days and days pass, adn the mermaid grows big... Meanwhile there's no sign of Daddy Turtle. What did Mummy mean when she said that Daddy would 'soon come'?