“It’s not a ‘he,’” said Mauder, “but a ‘she.’”

“Her name?”

“If you had asked that question earlier in the evening I could not have told you,” said Mauder, obviously enjoying the mystery he had created, “but since then my memory has been refreshed. The girl—and a most charming lady too—was my secretary for two years. I do not know what induced her to work, but I rather think she supported an invalid father.”

“What is her name?” asked Angel impatiently.

“Kathleen Kent,” replied the publisher, “and her address is——”

“Kathleen Kent!” repeated Jimmy in wide-eyed astonishment. “Angels and Ministers of Grace defend us!”

“Kathleen Kent!” repeated Angel with a gasp. “Well, that takes the everlasting biscuit! But,” he added quickly, “how did you come to know of our errand?”

“Well,” drawled the elder man, wrapping his dressing-gown round him more snugly, “it was a guess to an extent. You see, Angel, when a man has been already awakened out of a sound sleep to answer mysterious inquiries about an out-of-date book——”

“What,” cried Jimmy, jumping up, “somebody has already been here?”

“It is only natural,” the publisher went on, “to connect his errand with that of the second midnight intruder.”