Some people show evil as a great race horse shows breeding. They have the dignity of a hard chancre. Lewis did not show evil; he just looked nasty.
Walking home I tried to think what he reminded me of and there were various things. They were all medical except toe-jam and that was a slang word. I tried to break his face down and describe it but I could only get the eyes. Under the black hat, when I had first seen them, the eyes had been those of an unsuccessful rapist.