Walrus Books, North Vancouver, BC, 2010, 1st.  ISBN 978-1-77050-025-9.  Small trade soft cover, 124 pages including Glossary, followed by ads.  Unread copy; not remaindered.  ‘What has happened to Liv and Sophie’s sixteen-year-old brother, Mark?  The twins were so excited when he joined them at the Lucky Star Ranch, but now they discover that Mark has become silent and moody, and he totally refuses to ride a horse.  When a secret desert mission suddenly turns into a desperate attempt to dodge horse smugglers, Mark has to face his fears.  Can Mark, Liv, Sophie and their ranch kid friends help Mystery escape certain death?  And can they use their survival skills to withstand the worst the hostile wilderness can dish out – including a vicious sandstorm?’ (from rear wrap)