It was almost dark when young Dr. Phillips swung his sack to his shoulder and left the tide pool. He climbed over the rocks and squashed along the street in his rubber boots. The street lights were on by the time he arrived at his little commercial laboratory on the cannery street of Monterey. It was a tight little building, standing partly on piers over the bay water and partly on land. On both sides the big corrugated-iron sardine canneries crowded in on it.
(My mentor Howard Pease continues) Here the setting shows the protagonist as part of his environment. A further step gives us his name, and we learn that he is young. By implication we gather that Dr. Phillips is not a medical man but a scientist who runs a commercial laboratory on cannery row; therefore, he is no doubt a marine biologist.
Notice that he is in action. We glimpse the tide pool and the rocks on the beach. We do not see the town itself until the protagonist arrives at his laboratory. The time element is mentioned twice, but not by clock. This gives the impression that Dr. Phillips is a man who works until it is too dark to see. Notice, too, the active verbs climb and squash, both used without adverbs.