PRINTED IN THE UNITED STATES OF AMERICACONTENTSCHAPTERPAGE1[The Earthquake][1]2[The Mysterious Hitchhiker][11]3[Report from Interpol][18]4[Another Tremor!][30]5[Secret Cache][39]6[Brungarian Coup][46]7[Wall of Water!][55]8[A Suspect Talks][65]9[The Cave Monster][73]10[Energy from Planet X][83]11[An Electrical Christening][92]12[Exman Takes Orders][99]13[Disaster Strikes][106]14[Air-borne Hijackers][115]15[Kidnaped!][125]16[A Unique Experiment][137]17[An Urgent Warning][145]18[Earthquake Island][155]19[A Fiendish Machine][166]20[The Robot Spy's Story][177]The raiders transferred Exman to the enemy sub[CHAPTER I]THE EARTHQUAKE