Read it through once

“Look here!” he replied, pulling from his waistcoat a curiously-constructed pistol, having a double-edged spring knife attached to the barrel. “That’s a great tempter to a desperate man, is it not? I cannot resist going up with this every night, and trying his door. If once I find it open he’s done for; I do it invariably, even though the minute before I have been recalling a hundred reasons that should make me refrain: it is some devil that urges me to thwart my own schemes by killing him. You fight against that devil for love as long as you may; when the time comes, not all the angels in heaven shall save him!”