Divination

Once he drank the water, Alex found himself in another trance that showed him more visions. 

He saw the vague silhouette of a girl, which changed to another girl, and then another one.

He saw lightning crackle all around him, some came from heaven and some from somewhere else.

He saw a circle, one that shocked him to his core.

He saw himself losing a power that someone else gained.

He saw the truth behind his existence.

Alex woke back up. "What was that?" he thought. Compared to the other two visions, this one had more visions for him to see and was more sporadic. He didn't understand what those visions represented. 

What were the girls about? Were they real? Did this well know who he was going to meet? What about the lightning? What was that lightning for?

The feelings of the vision, rather than the vision itself were what remained with him after he was out of the trance so he didn't know what he had actually seen.