There is something seriously wrong with 12 year old Billy Shiel's mother. She has days when she can't get out of bed; she's so tired that living a normal life is impossible, and no one knows what is wrong with her. He is also seriously bullied at school by Jamie Watts and his gang. Billy is a 'fish boy' in the sense that he loves the sea and swimming and spends lots of time there. When, one day, he meets a mackerel who talks - Kezdodic, it says - he can't believe what is happening, and he also feels he can't tell any one. That is, until he meets Patrick. Patrick is a new boy in school, who can stand up to Jamie and his chums, and he and Billy soon become close friends. They share a love of nature, and in particular, Billy is an expert on the David Attenborough TV programmes. He talks to David in his mind constantly. Patrick is an expert on magic tricks, and is really good, which makes their classmates accept him. The two boys share a sort of secret idiom and a shared way of thinking that is totally believable and Patrick believes Billy's story about the mackerel and encourages him to go back to the sea to try to meet him again. They name the fish Bob, and back Billy goes, to meet Bob and the whole shoal of mackerel, and they swim together magically and wonderfully. The fish speak their own language, English, but different basic words, and Billy soon learns how to connect. When he comes out of the sea, he tells Patrick about his experiences, and together they plan further excursions. Patrick is a bit worried, though, and insists on giving Billy a set of dog tags to wear in case something goes wrong and he has to be identified. Other adventures follow, in which the fish make it clear to Billy that they want him to stay with them. He says no, and they abandon him, which means he must be rescued by the coastguard. His parents ground him - no more sea swimming, but this he can't take, and in a remarkable and very dramatic ending we see Billy learn that he must turn himself around 'reset his compass', that he and Patrick can handle Jamie, that his mum has ME, and while they don't know when she will recover, they know she will. This is a beautifully written, realism plus fantasy novel that will appeal to keen readers. Not the easiest of reads, it will repay the attention it needs. There are lots of soft black and grey illustrations, mostly of fish, which add to the atmosphere. A superb, long book with lots of interesting psychological ins and outs.