Aine and Fionn, secret agents from MAC, are back!
This time they are in Kerry where a mermaid is causing all sorts of trouble. Our wily agents have to find her and send her back to the Otherworld where she belongs.

With the help of a rather posh seagull, a celebrity dolphin and a captured goat they set out to stop this fiend. But can they do it before her irresistible song drives people on the rocks and out of their minds?