This knocked the props from under the whole theory he had built up to account for the disappearance of Esther McLean.  If Esther were not the widow of his uncle, then the motive of James in helping her to vanish was not apparent.  Perhaps he told the truth and knew nothing about the affair whatever.

But Kirby was puzzled.  Why had his uncle, who was openly engaged to Phyllis Harriman, married her surreptitiously and kept that marriage a secret?  It was not in character, and he could see no reason for it.  Foster had sent him to Golden on the tacit hint that there was some clue in the license register to the mystery of James Cunningham’s death.  What bearing had this marriage on it, if any?

It explained, of course, the visit of Miss Harriman to his uncle’s apartments on the night he was murdered.  She had an entire right to go there at any time, and if they were keeping their relation a secret would naturally go at night when she could slip in unobserved.

But Kirby’s mind wandered up and down blind alleys.  The discovery of this secret seemed only to make the tangle more difficult.

He had a hunch that there was a clue at Golden he had somehow missed, and that feeling took him back there within three hours of the receipt of the certificate.

The clerk in the recorder’s office could tell him nothing new except that he had called up Mrs. Rankin by telephone and she had brought up the delayed certificate at once.  Kirby lost no time among the records.  He walked to the Rankin house and introduced himself to an old lady sunning herself on the porch.  She was a plump, brisk little person with snapping eyes younger than her years.

“I’m sorry I wasn’t at home when you called.  Can I help you now?” she asked.

“I don’t know.  James Cunningham was my uncle.  We thought he had married a girl who is a sister of the friend with me the day I called.  But it seems we were mistaken.  He married Phyllis Harriman, the young woman to whom he was engaged.”

Mrs. Rankin smiled, the placid, motherly smile of experience.  “I’ve noticed that men sometimes do marry the girls to whom they are engaged.”

“Yes, but—­” Kirby broke off and tried another tack.  “How old was the lady?  And was she dark or fair?”

“Miss Harriman?  I should think she may be twenty-five.  She is dark, slender, and beautifully dressed.  Rather an—­an expensive sort of young lady, perhaps.”

“Did she act as though she were much—­well, in love with—­Mr. Cunningham?”

The bright eyes twinkled.  “She’s not a young woman who wears her heart on her sleeve, I judge.  I can’t answer that question.  My opinion is that he was very much in love with her.  Why do you ask?”

“You have read about his death since, of course,” he said.

“Is he dead?  No, I didn’t know it.”  The birdlike eyes opened wider.  “That’s strange too.”