Just the one. So I had just walked into a room, but the shadow took its time following. So I went back into the corridor to see how far behind it was. Then I got hit and I respawned in the corridor, while the shadow was in the new room. The door in-between I had previously unlocked was locked again. So the shadow could not follow because of locked door, and I couldn't go down to get the key, because I would get to far away from the shadow and die.