When Steve Smith was just a kid in school, in remedial English with four other kids, he had a teacher who helped change his life. He couldn’t read very well, and when he found a copy of a children’s book on the bus, he took it in to Miss Iles, to see if she would want to buy it from him so he could buy himself a snack after school. Instead, she told the class that the book had been banned in the school. And then she read it to them.

The book was Six on Goldtop Hill, written by Edith Twyford, the first in a series of books about the Super Six, 3 boys and 3 girls who go on adventures together. When they asked why the book had been banned, she explained that it was considered racist, sexist, xenophobic, and overly simplistic. But she started to think that there was something more to the book. She thought she had found a code.

Shortly after that, she went missing.

Steve hadn’t had a good home life, so it wasn’t a surprise that he fell in with a bad crowd. He was in and out of jail for years, when he was finally sentenced for a long stint in prison. It was there that he finally learned to read. Some college kids came in with a new system to teach them how to read, and it finally stuck with him. He was finally able to understand the world of books. And when he finally got out, he wanted to find out what had happened to Miss Iles after finding that code in the children’s book he found on the bus.

He tries to reconnect with the others in the class, to try to get them to talk about that time in school. He remembered that Miss Iles had taken them out of school, from London to Bournemouth, because of something she had read in the book. Steve remembers running around on a beach and later in an abandoned airfield, but he can’t remember much else. Clearly, something happened, because Miss Iles disappeared there. But what happened?

He starts with Paul, who didn’t want to talk about it, denied he was there that day. But Steve knew that he was—Miss Iles had had trouble getting the minibus started, and Paul figured it out since his dad was a mechanic. Next, he finds Shell on social media, Michelle now, the wife of a plastic surgeon with a big house and posh tea. But she refuses to get involved. Then he tries Nathan, who hadn’t spoken back then. He makes up for it now, but he doesn’t seem to know what happened that day. Donna wants to talk to him, was waiting for his call, but she doesn’t want to investigate alone. He thinks she’s scared.

Finally, Steve decides he needs to investigate himself. He goes to the library and tries to find books by Edith Twyford. They don’t have any of her books, but a young librarian helps him order one from eBay. And she looks up information on the writer and her husband. Edith Twyford wrote a lot of children’s books between 1939-1963. Her husband did the illustrations for her books as a hobby; he worked in the Home Office, a government job.

The more Steve investigates, the more he finds out about a government operation during World War II where they were going to take two billion dollars worth of gold bullion and store it in Canada until after the war. It was called Operation Fish, and one of the conspiracy theories around the Twyford Code is that it tells the location of all that gold. Steve wonders if this is true, as he is finding fish illustrations in different locations as he investigates. But there is no proof, and he finds no gold. And then he disappears.

Steve’s story is told in transcriptions from audio files on an iPhone 4. A copy of the files were sent to his son, a math professor at Brunel University, from a police investigator. Investigator Waliso asks him to read over the files and see if he can figure out what happened to his father. Professor Mansfield wasn’t raised by Steve. He hadn’t been a part of his life at all, until Steve had gotten out of prison. It was the professor’s old phone that Steve had been using for his audio recording, and he left his son a host of stories about Miss Iles and his time in remedial English, about his parents and brother, about his attempt to figure out the Twyford Code, and about his time in prison and the series of events that lead him there.

In the months that the professor reads and re-reads the transcription files, he discovers that the stories his father tells has a deeper meaning, and that the mystery of the Twyford Code may be something far different than everyone thought it was.

The Twyford Code is a complex mystery, told in fits and starts of audio recordings, with layers of truths and secrets that make the reader wonder what the real story is. There are so many twists and turns that the suspense never drops, the reveals just bringing you deeper into the story, making you think that you can finally wrap your head around what’s happening just before the rug is pulled out from under you again.

The Twyford Code, like Janice Hallet’s first novel The Appeal, is a masterful story told in unique ways, with bread crumbs dropped throughout that you can’t even see until the end. Hallet is a sort of plotting genius, creating puzzles within puzzles, and it’s up to the reader to figure out where the real truth is. I loved reading this book, but I think to truly appreciate it, I’ll need to read it all over again, just to see how she managed to put it all together so seamlessly. This book will sweep you up in a series of mysteries, and you will not believe where you end up. It’s pure magic!

Egalleys for The Twyford Code were provided by Atria Books through NetGalley, with many thanks.