brooding

Indeed, his mood was infectious, for I lay tossing half the night myself, brooding over this strange problem, and inventing a hundred theories, each of which was more impossible than the last.

Brooding over the case in that den of his, it suddenly struck him what absolutely damning evidence he could make against McFarlane by using that thumb-mark.

Now I knew that under ordinary conditions he no longer craved for this artificial stimulus, but I was well aware that the fiend was not dead but sleeping, and I have known that the sleep was a light one and the waking near when in periods of idleness I have seen the drawn look upon Holmes’s ascetic face, and the brooding of his deep-set and inscrutable eyes.

Yet even without knowing his brilliant record one could not fail to be impressed by a mere glance at the man, the square, massive face, the brooding eyes under the thatched brows, and the granite moulding of the inflexible jaw.