Sentence:  “H'm !" he said, "so, so&mdash;it is a tragedy in a prologue and three acts. I am going down this afternoon to see the <WSD>curtain</WSD> fall for the third time on what...will prove a good burlesque ; but it all began dramatically enough. It was last Saturday...that two boys, playing in the little spinney just outside Wembley Park Station, came across three large parcels done up in American cloth.nb...” 
Meaning of the word marked with <WSD> tags:  A similar piece of cloth that separates the audience and the stage in a theater.