"But the key—Carter sent me a photograph of that. Its curious arabesques were not letters, but seem to have belonged to the same culture-tradition as the parchment. Carter always spoke of being on the point of solving the mystery, though he never gave details. Once he grew almost poetic about the whole business. That antique silver key, he said, would unlock the successive doors that bar our free march down the mighty corridors of space and time to the very Border which no man has crossed since Shaddad with his terrific genius built and concealed in the sands of Arabia Petræa the prodigious domes and uncounted minarets of thousand-pillared Irem. Half starved dervishes—wrote Carter—and thirst-crazed nomads have returned to tell of that monumental portal, and of the hand that is sculptured above the keystone of the arch, but no man has passed and retraced his steps to say that his footprints on the garnet-strewn sands within bear witness to his visit. The key, he surmised, was that for which the cyclopean sculptured hand vainly grasps.