'He left them there to die...' Hal and Roger Hunt dive straight into danger on a specimen-collecting trip to Undersea City. But it's not just sharks and killer whales the brothers have to fear when they are plunged into the depths of another adventure.
- ISBN10 1782950176
- ISBN13 9781782950172
- Publish Date 2 May 2013 (first published 5 November 1970)
- Publish Status Active
- Publish Country GB
- Publisher Penguin Random House Children's UK
- Imprint Red Fox
- Format Paperback (B-Format (198x129 mm))
- Pages 288
- Language English