They reveal the location of the tunnel to Drust, as well as warning him that the demon masters are very close to crossing, and will be able to do so two days and two nights from that time.
They reveal the location of the tunnel to Drust, who claims that it can be reached by eight days of hard marching. However, when they concentrate, the Old Creatures sense that the demon masters are very close to crossing, and will be able to do so two days and two nights from that time.