The plot of "The Signalman" reaches a climax when signalman dies. As you know, the main characteristic of climax is that it is the most emotional part of a story that provides a lot of interest and suspense to a reader. The death of signalman is the highest point of emotional intensity of the plot as the loved protagonist unexpectedly (or undesirably) passes away and put an end to the story.
Some people are insecure, or downright untrustworthy of their surroundings. Usually, it's not your fault if they are fake towards you. They have usually adapted their fake selves on others that it becomes a normality.
