Explain how the story would have changed if saki had used the first-person point of view.

The point of view of "The Interlopers" is third-person omniscient narrator. For, the narrator taps into the thoughts and feelings of Ulrich von Gradwitz and Georg Znaeym, even though near the end of the narrative as suspense rises the narrator does not describe the inner workings of the men quite as much in order to create more suspense.

omniscient narrator--a narrator who knows everything that needs to be known about the agents and events...

quite an interesting way to teach topic sentences, because the answer to this question is the best definition of a topic sentence that one can present, it is as if answering the questions taught you how to do it, this is some real teaching, it is terribly well-done.

the topic sentence in this paragraph is:

topic sentences writers stay on track and keep a paragraph from becoming an aimless collection of sentences about an idea.

which incidentally tells you what a topic sentence should be.