“But why didn’t you want me to come?” I persisted.  “Why fight against your own heart?  Hilda, I am sure—­I know you love me.”

Her bosom rose and fell.  Her eyes dilated.  “Love you?” she cried, looking away over the bushy ridges, as if afraid to trust herself.  “Oh, yes, Hubert, I love you!  It is not for that that I wish to avoid you.  Or, rather, it is just because of that.  I cannot endure to spoil your life—­by a fruitless affection.”

“Why fruitless?” I asked, leaning forward.

She crossed her hands resignedly.  “You know all by this time,” she answered.  “Sebastian would tell you, of course, when you went to announce that you were leaving Nathaniel’s.  He could not do otherwise; it is the outcome of his temperament—­an integral part of his nature.”

“Hilda,” I cried, “you are a witch!  How could you know that?  I can’t imagine.”

She smiled her restrained, Chaldean smile.  “Because I know Sebastian,” she answered, quietly.  I can read that man to the core.  He is simple as a book.  His composition is plain, straightforward, quite natural, uniform.  There are no twists and turns in him.  Once learn the key, and it discloses everything, like an open sesame.  He has a gigantic intellect, a burning thirst for knowledge; one love, one hobby—­science; and no moral instincts.  He goes straight for his ends; and whatever comes in his way,” she dug her little heel in the brown soil, “he tramples on it as ruthlessly as a child will trample on a worm or a beetle.”

“And yet,” I said, “he is so great.”

“Yes, great, I grant you; but the easiest character to unravel that I have ever met.  It is calm, austere, unbending, yet not in the least degree complex.  He has the impassioned temperament, pushed to its highest pitch; the temperament that runs deep, with irresistible force; but the passion that inspires him, that carries him away headlong, as love carries some men, is a rare and abstract one—­the passion of science.”

I gazed at her as she spoke, with a feeling akin to awe.  “It must destroy the plot-interest of life for you, Hilda,” I cried—­out there in the vast void of that wild African plateau—­“to foresee so well what each person will do—­how each will act under such given circumstances.”

She pulled a bent of grass and plucked off its dry spikelets one by one.  “Perhaps so,” she answered, after a meditative pause; “though, of course, all natures are not equally simple.  Only with great souls can you be sure beforehand like that, for good or for evil.  It is essential to anything worth calling character that one should be able to predict in what way it will act under given circumstances—­to feel certain, ’This man will do nothing small or mean,’ ‘That one could never act dishonestly, or speak deceitfully.’  But smaller natures are more complex.  They defy analysis, because their motives are not consistent.”