Here's exciting, closely knit adventure with uranium runners that involves a detecting chase through Yukon territory with all the accoutrements of Arctic doings. Young Steve Blake and his mineralogist dad set out to track down mysteriously disappeared Uncle Paul, also a mineralogist, and when last heard from, on the trail of ""something big"". The gang they discover north of Whitehorse operates with hidden geiger counters. They keep tabs on anyone out for a strike of uranium oxide but fumble this time on account of divided loyalties and thus facilitate the Blakes' triumph.