the curtain comes down on (something)
Something ends. When the curtain comes down on the company after 50 years of business, a lot of people will be left jobless.
the curtain comes down on something
if the curtain comes down on something, it ends: On Saturday the curtain came down on another Olympic Games. Curtain in these idioms refers to the large curtain at the front of the stage in a theatre, which comes down at the end of a performance.