Mystery at Lynden Sands by J.J. Connington

When Cressida received her uncle's note that afternoon, she was both relieved and puzzled. Within less than a week she had been subjected to shocks and strains of such acuteness that she had almost lost the power of being surprised by anything that might happen; and Paul Fordingbridge's letter caused her hardly any astonishment, which she would certainly have felt had she been in a more normal condition. All that she gathered from it was that, after disappearing in a mysterious manner, he had returned and evidently needed her assistance. She was not particularly attached to him; but she was not the sort of person who would refuse her help to anyone in an emergency, even though that person had shown her very little sympathy in her own recent troubles.

She had a very fair idea of the rumours which had been running through the hotel, and she had no desire to advertise her meeting with her uncle. The final phrase in the note: "Come alone," was quite enough to suggest that he wished to keep the encounter secret. And she knew well enough that a plain-clothes constable had been detached to watch her; she had seen him once or twice when she had been passing through the entrance-hall, and had no difficulty in detecting the interest which he took in her movements. Unless she could contrive to give him the slip, he would follow her out to the Blowhole. Then she thought of the lady golfers' dressing-room, with its convenient door to the outside of the hotel, and a method of evasion suggested itself. She took the lift down; walked boldly past the watcher; turned down the passage and entered the dressing-room. Then, picking up her hat, blazer, and golfing-shoes, she slipped out of the side-entrance and hurried down one of the paths till she reached a place where she could change her slippers for her outdoor shoes.