Daily Chinese Idiom Guessing Game
Clues or traces that are tiny but can lead to the discovery of something hidden.
从挂下来的蜘蛛丝可以找到蜘蛛的所在，从马蹄的印子可以查出马的去向。比喻事情所留下的隐约可寻的痕纪线索。
清·王家贲《别雅序》大开通同转假之门，泛滥浩博，几凝天下无字不可通用，而实则蛛丝马迹，原原本本，具在古书。”
The detective found spider silk and horse tracks that eventually solved the case.