In the autumn of 1918, many of Dr. Admont Halsey Clark's colleagues were in France, tending to troops. Although commissioned as a first lieutenant in the medical reserve corps, he had heeded the U.S. surgeon general's request that he keep to his research.
It was lonely work.
The pathologist slept on a cot in his lab at Johns Hopkins Hospital, running experiments he hoped would reveal more about flu and its aftermath. Often the viral infection was followed by fatal pneumonia. He was studying streptococcus, a bacterium that causes it.
Little did Clark know that at 30, his age put him at great risk. Later it would be apparent that the 1918 pandemic unexpectedly sickened and killed people ages 15 to 35. Like him, many were robust young adults on their way up.
Clark could comfort himself with the thought that his wife and daughter were safely out of town. Also, the risk of exposure was part of his calling.
His dedication might have grown out of his upbringing. He was born in Japan into a missionary family -- one relative established the Camp Fire Girls; another edited the first newspaper in the Hawaiian language. Letters show he was raised on principles of humility and duty.
He worked his way through Oberlin College in Ohio, completed medical school at Hopkins and began pioneering research on diabetes. His associate professorship was rare for someone so young.
Clark stuck to his work even as the danger grew more apparent. His mentor, Hopkins pathologist William H. Welch, had investigated flu at Camp Devens near Boston and described harrowing deaths. At Camp Meade, the chief laboratory physician died.
Clark came down with the flu, but seemed to recover. Returning to his lab, he appeared more worried about a sick friend, Hopkins surgeon Ernest Gray, then about himself, according to a friend's account.
Yet Clark had a lot to lose. He had fallen in love with Janet Howell, the daughter of famed Hopkins physiologist William Henry Howell, and after marrying in 1917, he and Janet had had a baby in the spring.
As an outdoorsman, he had found a soulmate in Janet. They had camped as newlyweds. That fall, while he worked in Baltimore, she was in Maine.
When Gray died of the flu, Clark had barely enough time to send flowers before falling ill with pneumonia.
Admont Halsey Clark died Oct. 13, 1918.
Three days later, his mentor mourned the loss in a letter of condolence penned during Welch's own convalescence from the flu. It was addressed to Clark's father-in-law, William Henry Howell.
"He was one of the very ablest and finest men who have graduated from our school and would have attained the highest position in pathology," Welch wrote.
"He was such a splendid character and exerted such a fine influence, that our school could hardly sustain a greater loss among the younger generation."
The personal cost was great, too, in Clark's role as husband and father. Although his widow would have a career as a scientist and educator, she did not remarry. Janet Howell Clark bore up and moved forward. Her descendants say she seldom spoke about her loss to her daughter, or to the next generation.
"I grew up knowing my grandfather died in the epidemic and that he was working at the time, but I didn't know any details," says Jan Moller, one of three grandchildren. "The family never talked about it. It happened -- and was gone."