The well has run dry
Meaning
A source of supply, ideas, or energy has been completely exhausted.
Origin
Imagine ancient desert settlements, utterly dependent on their single well. When it ran dry, it wasn't just an inconvenience; it was a death sentence. The sheer suddenness and finality of that loss, the complete cessation of water, is where this phrase truly grips you. It paints a stark, unforgettable picture of utter depletion, a resource vanishing completely and irrevocably, leaving people with nothing but dust and despair.