There is a little water in it now.

You know we used to meet with it, down below, and water our horses at a pool close to that ruined village.

When we start, we can follow the road until we get close to the fort, and then crawl along in the water course, and take our chances.

If we should find it so blocked up that we can't get through, we must then see how we can get past the place in some other way.

If the gate is only barred, no doubt we should be able to overpower the sentry, and get the gate open before any alarm is given.
If it is locked, we must do the best we can.