Listening in a foreign language can get tiring fast, and most learners can't sustain focused attention on fresh material for more than a few minutes at a time. By breaking up the story into 2-3 minute segments, you can assimilate information much more effectively, and each listen will feel easier than the last. The final listen of a chapter should feel effortless, like freewheeling downhill on a bicycle: the natural sounds of the language will be baking into your ears while you catch a breath, before moving on to the next chapter.