How does Mr. Martin present himself to Ms. Barrows on the night of his visit to her apartment?

Mr. Martin at first presents himself as a modest little man not too much different from the person he appears to be at the office, except for the fact that he smokes cigarettes and drinks liquor. This is while he is still planning to murder Ulgine Barrows. She is surprised even at this difference in his personality. But while she is out of the room mixing drinks and he is looking around for something to kill her with, he has a sudden realization that he can do something much better. When she comes back with the drinks he pretends to be borderline insane. He tells her, among other things:

"I am preparing a bomb that will blow the old goat higher than hell....I'll be coked to the gills when I bump that old buzzard off."

Mrs. Barrows indignantly orders Mr. Martin to leave. She reports his behavior to their employer Mr. Fitweiler the next morning. But she ends up losing her own job because Mr. Fitweiler believe she must be insane to think that a mousy little man like Mr. Martin could have behaved the way she describes.