The story
Recorded since 1579, from quag + mire. The sense “perilous, mixed up and troubled situation” has been recorded since 1775. Alternatively, the word may apparently be a variation of the earlier quakemire, from quake + mire. Compare typologically Bulgarian тресавище (tresavište), Polish trzęsawisko, Russian тряси́на (trjasína) (akin to трясти́ (trjastí)); зыбь (zybʹ), зыбу́н (zybún) (<… Proto-Slavic *zybь).
Etymology from Wiktionary, CC BY-SA 4.0.