倒悬之危

dào xuán zhī wēi

lit. the crisis of being hanged upside down (idiom); fig. extremely critical situation

dire straits

倒

dào

to invert; to place upside down or frontside back

悬

xuán

to hang or suspend

之

zhī

(possessive particle, literary equivalent of 的[de5])

危

wēi

danger