Night Piece

I do not understand Poul Anderson's "Night Piece." Anderson's Introduction to the story in The Gods Laughed (New York, 1982) informs us that:

"...Night Piece is at least three concurrent stories, two of them symbolic." (p. 34)

- and that the story has:

a basic idea or assumption;
a problem consequent on the assumption;
a resolution of the problem.

The assumption, problem and resolution are handled not as narrative but with some of the techniques of Kafka or Capek because the significant action is within the viewpoint character's mind.

He converses with a woman at a bus stop, then with the bus driver, about whether the bus goes to Seventh Street. Are these conversations within his mind and is the number seven significant?

His experiments with an ESP amplifier have sensitized him to something outside human understanding. First, he seems to be directly aware of oceanic life and evolution.

Secondly, he recalls an interesting speculative conversation with his wife that seems to be relevant. In that conversation, he made two distinctions, first between the superman as envisaged by Nietzsche and Superior as the next stage of evolution, and secondly between five "...modes of behavior..." (p. 45), levels or layers of response to the environment:

tropism (I had to google this - it is how plants respond to heat, light etc);
reflexes;
instincts;
intelligence;
Superior (humanly unimaginable but "...of an ESP nature..." (p. 52), retaining only a modicum of reason as we do of tropism).

Superior, evolving on Earth, not elsewhere, would have diverged long ago and would be as unperceived by men as men are by mice, but ESP amplification has sensitized the viewpoint character to conflicts between two Superiors, whom he calls Aleph and Zayin, and ever since then he has been hunted by a creature that he imagines in detail, although knowing that it is not present as imagined. The oceanic feeling and the pursuit are his mind's interpretation of what he is experiencing.

How does he resolve the problem and what are the three concurrent stories?