The Rainhurst Project, despite seeming improvised and unrehearsed for the most part, actually had a screenplay and followed it closely. It was written by Joel Marzzarella, Darren Olah, and Brad Olah.

You can download and view the screenplay as a Microsoft Word document at the link below:
The Rainhurst Project Screenplay

Here’s an excerpt from the screenplay:

INT. RAINHURST CONTROL ROOM – DAY
Camera switches on, the group is looking around Rainhurst, they come upon a room with some switches on the wall.
KEVIN
Guys check out these switches… They’re totally broken.
Kevin begins flipping the smaller switches, nothing happens. Kevin grabs a larger one and pulls it down. A rumbling begins as the huge generators in the other room begin turning. A metal fragment flies into the control room and almost hits the group.
JAMES
Turn it off!
Kevin flips the switch to the way it was, the generators stop moving.
KEVIN
Wow, I’m surprised this stuff still works.
JAMES
More looking, less touching, please…
Camera switches off
INT. RAINHURST BATHROOM – DAY
Camera clicks on, looking at a smashed toilet.
KEVIN
So we found the bathroom.
JAMES
(sarcastically)
Yeah, I think it’s out of order.
LIZ
Ewwww! I just stepped in something gross!
James looks over to see a slimy smashed egg under Liz’s foot. The slime is glowing slightly blue.
LIZ
(sarcastically)
I bet it’s ectoplasm… from a ghost.
JAMES
You need to take this a bit more seriously…
KEVIN
(Pokes slime)
Ewww…
JAMES
Guys, were you even listening to me when I said less touching?