Taking your hard-won prizes (the eye of the beholder and the purple worm egg), you begin the long trek back to Vizeran's tower. Partway through the journey, those who joined your travels from the beholder's lair split off and go their own way.
When you return, the door opens of its own accord and you head into Vizeran's sitting room, "So you've returned," he says, "Did you get the objects I asked for?"