Possible Clues:

• Stand-in on bed creating a minor story
• Revamped pub has opening outside? It's a minor story
• It's not the main story
• In Twelfth Night, this involves Sir Toby, Sir Andrew and Maria
• Side story in, eg, a play
• Story-within-a-story in a novel
• Underneath bed in part of play
• Part of story having two vessels crossing lake
• Pub blasted into space? That's not the main story
• Second story?