"I can't tell you," she said quietly.
"You promised."
"I break the promise."
Tony looked wistfully at his companion. That the perplexing words had been spoken with a definite meaning he had felt sure from the moment when he had remembered them. And her refusal to explain proved to him that the meaning was a very serious one--one indeed which he ought to know and take into account.
"I ask you to explain," he urged, "because I am going away, and I am leaving Millie behind."
Pamela was startled. She turned quickly towards him.
"Must you?" she said, and before he could answer she recovered from her surprise. "Never mind," she continued; "shall we ride on?" and she put her horse to a trot. It was not her business to advise or to interfere. She had said too much already. She meant to remain the looker-on.
Stretton, however, was not upon this occasion to be so easily suppressed. He kept level with her, and as they rode he told her something of the life which Millie and he had led in the big lonely house in Berkeley Square; and in spite of herself Pamela was interested. She had a sudden wish that Alan Warrisden was riding with them too, so that he might hear his mystery resolved; she had a sudden vision of his face, keen as a boy's, as he listened.
"I saw Millie and you a few nights ago. I was at a dance close by, and I was surprised to see you. I thought you had left London," she said.
"No; but I am leaving," Stretton returned; and he went on to describe that idyllic future which Millie and he had allotted to themselves. The summer sunlight was golden in the air about them; already it seemed that new fresh life was beginning. "I shall breed horses in Kentucky. I was recommended to it by an East End parson called Chase, who runs a mission on Stepney Green. I used to keep order in a billiard room at his mission one night a week, when I was quartered at the Tower. A queer sort of creature, Chase; but his judgment's good, and of course he is always meeting all sorts of people."