Fortenminutestheygropedslowlyalongawindingpassage，untilatlengththeycametoacloseddoor。Hereheheardherfumblingwithakey，andpresentlycamethesoundofametalboltgratingagainstmetal。Thedoorswunginonscrapinghinges，andtheyentered。
\"Youwillbesafehereuntiltomorrownight，\"shesaid。
Thenshewentout，and，closingthedoor，lockeditbehindher。
WhereTarzanstooditwasdarkasErebus。Notevenhistrainedeyescouldpenetratetheutterblackness。
Cautiouslyhemovedforwarduntilhisout—stretchedhandtouchedawall，thenveryslowlyhetraveledaroundthefourwallsofthechamber。