A claustrophobe's bedroom

"Speaking of SOCO," said Miss Flava.  "Isn't it about time we passed this over to them?  This house is getting weirder with every room we go through.  We should let them look over it and find all its little secrets out before we accidentally lose any of them."
"If there are any left," said Playfair.  "Don't forget that we've no idea what Ronald and his belle were up to in the house before we arrived."
"The door was locked," said Miss Flava.  Playfair had started up the stairs, not bothering to check to see if she was following.
"But when?" said Playfair.  He vanished onto the landing at the top of the stairs, leaving Miss Flava stood there wondering to herself if he was right.  If Ronald had had a key then locking the door behind him when he came into the house would be only natural.  They only had his word for how long he'd been there, after all.  Grimacing slightly she hurried after Playfair, telling herself that she had to keep and eye on him and make sure he wasn't adjusting the evidence to suit himself.
At the top the landing had three doors, all of which were ajar, and a second staircase led up again, over the staircase she'd just come up.  Playfair was just coming out of the left-most room.  He shrugged when he saw her.
"Bathroom," he said.  "Small, mean, looks like it might be for guests.  Toilet paper is shiny."  He poked his head round the next door, but didn't bother going in.  "Bedroom, small, mean, single bed, cover looks dusty," he said.  "Ever get the feeling we're on the guest floor?"
"For what guests?" said Miss Flava.  "As I said downstairs when you weren't listening to me–"
"Bedroom, small, meaner, single bed with a bare mattress and a broken lightbulb," said Playfair from the doorway of the third room.  "What was that?"
"I said, when you weren't listening to me I already asked you what guests our magician could have had?"
"Good question.  Single people, I should think.  There's not a double bed in sight."
"This is stupid, Playfair.  The man never had guests!"
"So why does he have guest rooms?"  Playfair started up the second flight of stairs.
"For show?"  Miss Flava knew she was guessing wildly, but she hated Playfair's persistent questions that always seemed to last longer than anyone could keep answering for.
"How very Edwardian," said Playfair, his voice echoing oddly.  "Now, this is interesting."  Miss Flava followed him up the stairs, cursing softly under her breath.  As she ascended she got a sensation of space, and couldn't see any walls through the balusters, so assumed that the landing was abnormally large.  It was only as she reached Playfair that she saw that there were no intervening walls, just a wide open space with concrete supporting pillars.  The floor was carpeted in beige, but otherwise there was almost nothing else up there.
"That's a sleeping bag," she said, pointing to the crumpled pile of satiny-looking fabric in the middle of the floor.  "That's probably a pillow caught up in it."
"Best to check," said Playfair.  He kicked the sleeping bag aside, and a sad, lumpy pillow fell over with a soft, slack sound.
"First attempt at a theatre?" She looked around some more, but found nothing else, not even cupboards or shelves.  The windows had blinds, but they were all drawn up.
"Or a claustrophobe's bedroom," said Playfair.  "I wonder if he ever did any magician-in-a-cabinet tricks."