Read it through once

“It cannot be,” quoth she, “that so much guile”— She would have said “can lurk in such a look.” But Tarquin’s shape came in her mind the while, And from her tongue “can lurk” from “cannot” took. “It cannot be” she in that sense forsook, And turned it thus: “It cannot be, I find, But such a face should bear a wicked mind.