The platoform shown above is a wagon. It is an 18 inch high octagon with a smaller octogal post in the middle. A black water pump is mounted to it. A container of water is hidden inside the wagon so that the pump can draw water up.
We can use something like these, but we will paint them to match the string or just black. Some knots or frays added to the string might further conceal these magnets.

There are ropes or strings shown hanging down from above with an octagonal footpring. Some of these will be metal rebar masquerading as ropes. The few carefully placed metal ones will extend down to about seven feet above the deck. There will also be small, flat, metal plates screwed to the floor that are hidden within the paint.

The string that father uses will have small, strong magnets disguised as frays or knots in the rope. These will be placed at key points in the string so that he can swifly and elegantly sketch out a room made of string in the air.

There might be a ready-built square of string that father can hang to make a window, too.

A classic old elevator lift with collapsible gate in hotel. Interior architectural element. Antique and vintage design.

I propose vintage elevator doors. This will allow us to place them at the boundary of the playing space without blocking sightlines, and we will not need to cheat the rain effect’s placement. It can remain inside the elevator. These doors could split in the middle and open or they can open to one side only,

4mm faceted beads, inexpensive on Amazon. 2000 for $8

I have specific thoughts technically about the rain. However, if it happens that real water is not reasonable for the shop to do for any reason, we might consider raining small acrylic crystal beads instead. This would be similar to the old-fashioned effect of using rice, but with less risk of attracting vermin or accidentally creating glue when mopping. I do hope to use real water.

The staircase includes the pole and railings show that hug tightly to the center column. Eurydice starts above the vom by Costume Storage. She steps onto the top/center octagon +81″ She should hold onto the pole shown while doing so. She can slump down onto her knees or a sitting position to slowly and dramatically tumble down the stairs. The stairs are most likely straight-castered and might have a wagon lock. They can be pushed to the center of the maze either before she falls or as she falls. This staircase is intended for slow dramatic movement.