While scuba diving off the coast of Portugal, Penny and Mark and their friend David discover a gold smuggling ring inside an ocean cave and find themselves in great danger as they try to evade their pursuers through unfamiliar tunnels.
- ISBN10 1561794813
- ISBN13 9781561794812
- Publish Date 23 September 1996
- Publish Status Active
- Out of Print 17 December 2011
- Publish Country US
- Imprint Focus on the Family Publishing
- Format Paperback (B-Format (198x129 mm))
- Pages 127
- Language English