He was in and out, principally observing the comings and goings of Mr.Gurney.

He found what he naturally suspected, that Mr.Gurney and Stephanie spent hours here at peculiar times--after a company of friends had jollified, for instance, and all had left, including Gurney, when the latter would quietly return, with Stephanie sometimes, if she had left with the others, alone if she had remained behind.

The visits were of varying duration, and Kennedy, to be absolutely accurate, kept days, dates, the duration of the hours, which he left noted in a sealed envelope for Cowperwood in the morning.
Cowperwood was enraged, but so great was his interest in Stephanie that he was not prepared to act.

He wanted to see to what extent her duplicity would go.
The novelty of this atmosphere and its effect on him was astonishing.
Although his mind was vigorously employed during the day, nevertheless his thoughts kept returning constantly.

Where was she?
What was she doing?
The bland way in which she could lie reminded him of himself.
To think that she should prefer any one else to him, especially at this time when he was shining as a great constructive factor in the city, was too much.