Investigate the noise behind you
From Create Your Own Story
Before going any deeper into the tomb, you think it prudent to investigate the noise behind you. It may have been nothing...or it may have been something. Making sure your weapons are secure, you cautiously begin making your way back up the tunnel. You have not gone far before you hear something. This time you're sure. It was definitely a noise, sounding almost like footsteps.
As you round a sharp corner and emerge in the wider part of the passage, you stare in horror. The skeletons that had been lining the sides of the tunnel have now all gotten up and are marching steadily down the passage towards you, weapons in their bony hands and soulless grins on their undead faces. Apparently, whoever rules this tomb does not like visitors, and has power over the undead to enforce its will.