Which sentence in this excerpt from sir arthur conan doyle's "the adventure of the speckled band" portrays the theme of evil? "alas! " replied our visitor, "the very horror of my situation lies in the fact that my fears are so vague, and my suspicions depend so entirely upon small points, which might seem trivial to another, that even he to whom of all others i have a right to look for and advice looks upon all that i tell him about it as the fancies of a nervous woman. he does not say so, but i can read it from his soothing answers and averted eyes. but i have heard, mr. holmes, that you can see deeply into the manifold wickedness of the human heart. you may advise me how to walk amid the dangers which encompass me." "i am all attention, madam." "my name is helen stoner, and i am living with my stepfather, who is the last survivor of one of the oldest saxon families in england, the roylotts of stoke moran, on the western border of surrey." holmes nodded his head. "the name is familiar to me," said he. "the family was at one time among the richest in england, and the estates extended over the borders into berkshire in the north, and hampshire in the west. in the last century, however, four successive heirs were of a dissolute and wasteful disposition, and the family ruin was eventually completed by a gambler in the days of the regency. nothing was left save a few acres of ground, and the two-hundred-year-old house, which is itself crushed under a heavy mortgage. the last squire dragged out his existence there, living the horrible life of an aristocratic pauper; but his only son, my stepfather, seeing that he must adapt himself to the new conditions, obtained an advance from a relative, which enabled him to take a medical degree and went out to calcutta, where, by his professional skill and his force of character, he established a large practice. in a fit of anger, however, caused by some robberies which had been perpetrated in the house, he beat his native butler to death and narrowly escaped a capital sentence. as it was, he suffered a long term of imprisonment and afterwards returned to england a morose and disappointed man.