And presently Sarah Judd came out upon the lawn to ask Mrs. Conant’s further instructions and this gave Agatha the desired opportunity to examine her closely.  The inspection must have been satisfactory, for an expression of distinct relief crossed the lovely face.

That Sunday evening they all went down to the Bigbee place in Miss Lord’s motor car, where the lady entertained her guests at a charming luncheon.  The Bigbee place was more extensive than Hillcrest Lodge, as it consisted of a big, rambling residence and numerous outbuildings; but it was not nearly so cosy or homelike, nor so pleasantly situated.

Miss Lord’s maid, Susan, was somewhat a mystery to the Hillcrest people.  She dressed almost as elaborately as her mistress and performed her duties grudgingly and with a scowl that seemed to resent Miss Lord’s entertaining company.  Stranger still, when they went home that night it was the maid who brought out the big touring car and drove them all back to Hillcrest Lodge in it, handling the machine as expertly as Agatha could do.  Miss Lord pleaded a headache as an excuse for not driving them herself.

Sarah Judd opened the door for them.  As she stood under the full light of the hall lamp Mary Louise noticed that the maid Susan leaned from her seat in the car and fixed a shrewd glance on Sarah’s unconscious face.  Then she gave a little shake of her head and drove away.

“There’s something queer about the folks at Bigbee’s,” Mary Louise confided to Irene, as she went to her friend’s room to assist her in preparing for bed.  “Agatha Lord kept looking at that velvet ribbon around your neck, to-night, as if she couldn’t keep her eyes off it, and this afternoon she seemed scared by the news of Sarah Judd’s arrival and wasn’t happy until she had seen her.  Then, again, that queer maid of Agatha’s, Susan, drove us home so she could see Sarah Judd for herself.  How do you account for all that, Irene?”

“I don’t account for it, my dear.  You’ve been mixed up with so many mysteries that you attach suspicion to the most commonplace events.  What should there be about Sarah Judd to frighten anyone?”

“She’s a stranger here, that’s all, and our neighbors seem suspicious of strangers.  I’m not questioning poor, innocent Sarah, understand; but if Agatha and her maid are uneasy about strangers coming here it seems likely there’s a reason for it.”

“You’re getting morbid, Mary Louise.  I think I must forbid you to read any more of my romances,” said Irene lightly, but at heart she questioned the folks at Bigbee’s as seriously as her friend did.

“Don’t you think Agatha Lord stole that missing book?” asked Mary Louise, after a little reflection.

“Why should she?” Irene was disturbed by the question but was resolved not to show it.

“To get the letter that was in it—­the letter you would not let me read.”

“What are your affairs to Agatha Lord?”