From March and April of 1935.

Land of Always-Night

With the fate of America hanging in the balance, Doc Savage and his fearless crew battle a hideously white-faced man named Ool who kills merely with a touch of his finger. The only clue to his diabolical power is a mysterious pair of dark goggles which brings death to whomever possesses them. The trail leads to a fabulous lost super-civilization hidden deep in the bowels of the earth, where Doc Savage and his fabulous five face their supreme challenge.

The Spook Legion

The entire city of New York is swept up in a wave of terror, as an evil international conspiracy devises a crime so sinister that only Doc Savage and his five mighty cohorts can halt its fiendish plan. Led by a phantom master criminal with stupefying supernatural powers, the conspiracy sets trap after trap for Doc. Finally, in a fantastic underground empire, the fearless bronze giant and his courageous crew must fight for their lives against a diabolical enemy that cannot even be seen.