The Triple A's Check It Out

Three children, Astra, Andrew and Annabel, who live on Mars, visit the Martian moon Phobos with their mother. Andrew enters a chess tournament there, while Astra and Annabel explore the moon.

Phobos is like a city in space, with tunnels and subways all through it. It is also the main space station for the area.

They make friends with an older boy called Mark and he asks for their help with a mystery he's involved in. As events unfold, they get drawn further and further into an exciting adventure, tracking down a gang of dangerous ice smugglers. Eventually they decide to try and catch the gang red handed using a trick chess opening called 'The Oh My God Trap'.
The recomended age group is 8-14 years.

http://mysite.wanadoo-members.co.uk/thetripleas/index.html