The story:
A Dr. Heg is visiting the Jungle Patrol to write a book about the organisation, but is in reality a spy sent by a foreign power to catalogue the force prior to an invasion. To achieve this, the spy needs to solve the riddle of the Secret Commander, i.e. the Phantom.

Through various means the resourceful spy soon reaches his objective and can start playing havoc with the Jungle Patrol and the Phantom, who is facing lawlessness on all fronts in the jungle unless the situation can be brought under control fast...