Nosing around

Miss Flava and Playfair left Ronald tugging at his sister-in-law's leg and walked to the stage at the back of the room.  The curtains were drawn, and Calamity was still sitting beneath the trestle tables and had nearly finished a whole tray of sandwiches.  They looked at each other and decided silently that they'd leave her where she was for now.  Then they looked at the apron, which was about three feet high.
"Climb, or find stairs?" asked Miss Flava, sure that she could get up on the apron without trouble.
"Stairs," said Playfair after a moment's hesitation.  "Technically, moving the curtains counts as interfering with the scene of the crime."
"Do you think SOCO's been here yet?" asked Miss Flava as they both turned to the left, where the shadows suggested that there might be doors.
"Hah!  I don't think anybody but us has been here yet," said Playfair.  "Except maybe to ring the front doorbell and then write down in a little notebook that no-one appeared to be in at the dead man's residence."
"You're not giving the police in Little Haversham much credit, are you?" said Miss Flava.  They located two doors in the gloom at the side of the room, one appearing to lead out into the rest of the house, and being locked; the other was smaller, flimsier, and looked as though it might lead to the back of the stage.  Playfair gripped the handle firmly and opened the door with a shove.  It scraped along the floor for a few inches then moved freely, so he ended up slamming it back against the wall.  Calamity barked once, and then presumably went back to eating the sandwiches.
"They've not given me any reason to," said Playfair looking through the doorway.  "It's been three days at least, and they've not checked the house out.  That's given this upper-class twit a chance to get in with his simple sister and do god-knows-what in here.  We could be missing valuable clues because he's been tidying up or putting them in the sandwiches when his sister's not looking."
The doorway opened onto a small ante-chamber that was essentially a wide, short corridor with lots of shelves on both sides.  The shelves were lined with props for tricks, and some parts had been fitted with doors to turn them into cupboards.  Playfair opened the first and found several stacks of playing cards; the next was contained stacks of oversized playing cards.  A third cupboard contained a realistic severed head that seemed to eye Playfair back as he stared at it.
"Sister-in-law, not sister," said Miss Flava.  She was looking at the shelves on the other sides with their little machines, linkages, and boxes of nuts, bolts and washers.  "And... damn, does that mean we should have been treating the sandwiches as evidence?  You did say they looked like ham, and we've pretty much believed Ronnie when he said they were mackerel mayonnaise."
Playfair took the severed head out of the cupboard, a little carefully as it proved to be heavier than he was expecting.  Miss Flava turned to see why he hadn't answered, and took a step back, her hands coming up protectively in front of her.
"My God, Playfair, what is that?"
"Latex skin," said Playfair examining it, "over a metal frame I think.  There's a switch here...."
He pressed it and the head seemed to come to life, a soft interior glow making the flesh seem warmer and more human and the eyes blinking a couple of times.  The lips moved, and a hint of a pink tongue seemed to lick them.
"That's creepy!  Put it back, Playfair.  It's not evidence."
"We don't know what is and isn't evidence yet," said Playfair, but he pressed the switch again and put the head back in the cupboard anyway.  He closed the door on it.
"You might be right about the sandwiches," he said.  "But we've got a lot of them in Calamity now, so there's probably no call for worry."
Miss Flava considered that a potentially dead police dog was certainly cause for worry, but couldn't be bothered arguing with Playfair over it at the moment.  They carried on, walking through the corridor into the wings of the stage.  Towering curtains of black cloth now created entrances onto the stage that prevented the audience from seeing through to the wings or the prop room, and allowed the performers to move on and off stage as though vanishing from the world.  There was enough room for about four people to stand in the wings before it started getting crowded, and there was a small prompter's desk with a blue-shaded light-bulb tucked into the corner.
What they could see of the stage through the curtains was much more interesting though.