[Shadow Stranger]

It only happens in the Pyramid? That is odd, I have never heard of a problem like this before. Certainly not one that always happens.
I never play with only character, so I have no special insight into this problem.
Teleport or Vanish may work, I don't know. In the Crypt, the problem area near F'lokis Ra happens at a point in the game where the party is way too low in level to have spells like Vanish or Teleport.