midnight
I replied that though it was not the Aztec habit to march and fight at night , such things were common enough among white men as they had seen already , and that because the Spaniards knew it was not their habit , they would be the more likely to attempt escape under cover of the darkness , when they thought their enemies asleep . Therefore I counselled that sentries should be set at all the entrances to every causeway . To this Cuitlahua assented , and assigned the causeway of Tlacopan to Guatemoc and myself , making us the guardians of its safety . That night Guatemoc and I , with some soldiers , went out towards midnight to visit the guard that we had placed upon the causeway . It was very dark and a fine rain fell , so that a man could see no further before his eyes than he can at evening through a Norfolk roke in autumn . We found and relieved the guard , which reported that all was quiet , and we were returning towards the great square when of a sudden I heard a dull sound as of thousands of men tramping . ` Listen , ' I said .