山穷水尽 [- qiónɡ shuǐ jìn]the end of hills and rivers; be at [on] one's last shift [shifts]; be at [come to] the end of one's resources; be at [come to] the end of one's rope; come to a dead end; the condition that comes when one can do no more; where the mountains and the rivers end:
•¶ 处于山穷水尽的地步 be on one's bones
•¶山穷水尽， 豁然开朗。 An apparently blind alley leads suddenly into an open space.