You have reached a high, seamless, black wall that stretches from horizon to horizon. It is very cold near the wall, and you can see what appear to be a myriad of minute pixellated patterns forming and disolving rapidly on the sheer black face. There appears to be no way through or over...

As you stand here pondering your options, you hear a single raucous "caw". A large crow or raven suddenly appears overhead, looks down disdainfully, and flaps off in the direction of the ruined stone tower you passed earlier this morning.