midnight
The incline , moreover , is rapid , and from time to time we come to places where the ridge is so broken and insecure that we have to dismount , let our mules go first , and creep after them on our hands . At the head of the file is an Indian who rides the _ madrina _ -LRB- a mare -RRB- and acts as guide , next come Gondocori , myself and Gahra , followed by the other mounted Indians , three or four baggage-mules , and two men on foot . We have been going thus nearly an hour , when a sudden and portentous change sets in . Murky clouds gather round the higher summits and shut out the sun , a thick mist settles down on the ridge , and in a few minutes we are folded in a gloom hardly less dense than midnight darkness . `` Halt ! '' shouts the guide . `` What shall we do ? ''