Mrs. Kesserich nodded with solemn appreciation in the gathering darkness. "But now he was coming home, his work done. It was early evening, very chilly, but Hani and Hilda felt they had to ride down to the station to meet their brother. And although she dreaded it, Mary rode with them, for she knew how delighted he would be at her cantering to the puffing train and his running up to lift her down from the saddle to welcome him home. "Of course there was Martin's luggage to be considered, so the station wagon had to be sent down for that." She looked defiantly at Jack. "I drove the station wagon. I was Martin's laboratory assistant." She paused. "It was almost dark, but there was still a white cold line of sky to the west. Hani and Hilda, with Mary between them, were waiting on their horses at the top of the hill that led down to the station. The train had whistled and its headlight was graying the gravel of the crossing. "Suddenly Mary's horse squealed and plunged down the hill. Hani and Hilda followed--to try to catch her, they said, but they didn't manage that, only kept her horse from veering off. Mary never screamed, but as her horse reared on the tracks, I saw her face in the headlight's glare. "Martin must have guessed, or at least feared what had happened, for he was out of the train and running along the track before it stopped. In fact, he was the first to kneel down beside Mary--I mean, what had been Mary--and was holding her all bloody and shattered in his arms." A door slammed. There were steps in the hall. Mrs. Kesserich stiffened and was silent. Jack turned. The blur of a face hung in the doorway to the hall--a seemingly young, sensitive, suavely handsome face with aristocratic jaw. Then there was a click and the lights flared up and Jack saw the close-cropped gray hair and the lines around the eyes and nostrils, while the sensitive mouth grew sardonic. Yet the handsomeness stayed, and somehow the youth, too, or at least a tremendous inner vibrancy. "Hello, Barr," Martin Kesserich said, ignoring his wife. The great biologist had come home. III "Oh, yes, and Jamieson had a feeble paper on what he called individualization in marine worms. Barr, have you ever thought much about the larger aspects of the problem of individuality?" Jack jumped slightly. He had let his thoughts wander very far. "Not especially, sir," he mumbled. The house was still. A few minutes after the professor's arrival, Mrs. Kesserich had gone off with an anxious glance at Jack. He knew why and wished he could reassure her that he would not mention their conversation to the professor. Kesserich had spent perhaps a half hour briefing him on the more important papers delivered at the conferences. Then, almost as if it were a teacher's trick to show up a pupil's inattention, he had suddenly posed this question about individuality. "You know what I mean, of course," Kesserich pressed. "The factors that make you you, and me me."