I recently realised that I adore this trope. You know, like>! killing a npc surgeon!< in The Last of Us and its consequences in Part 2. Or >!the bagel!< in the recent Spiderverse movie. Or even Jason Momoa character in Fast X.

Are there the same ideas in any book series, where a character does something slightly noticeabale in the first book but it has long-range consequences and becomes the main plotpoint?