“On the doctor of the late lady. He was willing to see me when I could persuade him that his suspicions were right and that his patroness had really been removed by foul means. Then he told me quite a lot about the very odd person she was. She was shrewd in her way. She kept her own doctor and she paid him handsomely and took the complementary precaution of not remembering him in her will. Yes, he had every reason for keeping her going and being angry at her being gone. She was keen on staying here and not only that but on keeping young. But her colorfulness in dress was something more, he told me, than simply ‘mutton dressing itself up to look like lamb.’ She was color-blind and like that sort—the red-green colorblindness—she was very loath to admit it. That bright green dress of the photo pretty certainly seemed to her bright red.”

I was still at a loss and let the old man see it.

“Now comes Hess’s third neat piece of work. Note these facts: the aunt is persuaded to come to the garden—just to show that the nephew has turned over a new page and is being the busy little bird lover—sure way to keep in the maiden lady’s good graces. He takes her round.” Suddenly Mr. Mycroft stopped and picked up the celluloid red crescent. “Many color-blind persons have eyes that do not like a glare. The thoughtful nephew, having led auntie round the garden, takes her up the bridge to view the dear little birdie’s home. She has to gaze up at it and he has thoughtfully provided her with an eye-shade—green to her, red to him, and red to something else. “Certain species of hummingbirds are particularly sensitive to red—all animals, of course, preferred to any other color. When young these particular hummingbirds have been known to dash straight at any object that is red and thrust their long bill toward it, thinking no doubt it is a flower. They will dart at a tomato held in your hand. Well, the aunt is gazing up to see the birdie’s home; she’s at the top of the bridge, just where you stood. Nephew has gone on, sure that aunt is going to follow. He is, in fact, now down by that lower step. He just treads on the concealed black thread. The door flies open, the little feathered bullet which had been brooding in the dark sees a flash of light and in it a blob of red. The reflex acts also like a flash. It dashes out right at Miss Hess’s face. Again a reflex. This time it is the human one. She staggers back, hands to face—not knowing what has swooped at her—the flight of some of these small birds is too quick for the human eye. Of course she falls, takes her sup of the water, goes home shaken, no doubt not feeling pleased with nephew but not suspicious. After a fortnight we have a condition of stasis. The sound, but naturally not very progressive doctor, sees no connection. The police and public are also content. Nevertheless, she dies.”