Rod had been looking at Mary Thorn more or less casually ever since he was a leggy boy in knickers and she a slim elf in abbreviated gingham dresses. But he had never been so conscious of her as now. So late as yesterday he had regarded her without personal awareness of sex. How was it, he wondered, that a few words from his father, a cryptic hint or two, could make everything different? Nothing had happened. Yet he knew that a different quality had entered their companionship. A boy and a girl could play together without thinking of themselves as male and female. A man and a woman couldn't. His father had warned him that he was a man and should comport himself accordingly. As if a man's natural instinct was to run amuck! Perhaps that was the truth. Rod smiled uneasily at the notion. He was not precisely an unsophisticated youth, but he could scarcely comprehend that there is only a shadowy border between the frank, sexless affections of childhood and the uneasy glow of maturing passion. He had never nursed a libidinous thought about Mary Thorn. And yet-- His eyes rested on her with a new sort of gauge. She sat staring down Cardero Channel, her hands in her lap, not so much intent on some distant object as deep in one of those long, thoughtful silences into which she now and then retired,--a characteristic that Rod liked because it was something he himself often did. Her hair was a brown smoothness about her head, tied back with a narrow ribbon. She was very pretty, Rod decided critically, prettier than any girl he knew. But something more than superficial prettiness attracted him. He didn't know what. It eluded him. She had a woman's bosom and neck. Her body was made up of harmonious contours. Her expression, absent, reflective, gave him the feeling that he looked at maturity and wisdom. It surprised him to think that such an aspect of her had never struck him before. Looking at her, he suddenly felt a queer, constricted feeling in his breast. He desired all at once to touch her, to rest his fingers lightly on that delicately tinted skin. She would laugh at him. He wondered if she would. He wondered what she thought about, locked up in herself like that. What went on in her mind that brought tiny puckers of concentration in her forehead? Was she as suddenly acutely conscious of him, in a disturbing physical sense, as he was of her? And he wondered futilely why he should be troubled by such unaccustomed thoughts and sensations now, when so late as yesterday they two had sprawled together on the mossy benches of Little Dent, laughing and chattering like two boys bent on innocent adventure in the world of boyish action.