Film synopsis/plan - updated

The film opens with the main character in a meeting room, the door shutting as footsteps of others leaving can be heard and they sigh as they sort out some papers on the desk. Dragging themselves to their feet, they move over to the door, and push the handle to open it. It clicks and doesn't open. They frown and try again, this time putting more weight behind it, pushing harder. They can be seen getting more panicked as they start to hit the door and shout for help. Sound of their heartbeat, out of focus parts, slowly moving. The sound builds up of them shouting and slamming against the door again until it suddenly goes silent and there's a cut to them sitting against the door, slumped looking tired, their head in their hands (time has passed). Hear their heavy breathing, ambient noise of the room, birds etc, all heightened. It's visibly darker outside. Cuts between shots during the day, then night, then day again, sense of time passing but quite quickly. Trying to sleep when they hear a noise coming from the small cupboard (there will have been a shot of them previously looking in it but it's empty. There's a buildup of scratching, crawling, banging noises from in the cupboard, they look terrified-the noises keep increasing and they shove the table against the door-advancing away. It is dark outside and the lights switch off - sound of the cupboard, their heavy breathing/cries for help. The light flickers, we see the shadow of something coming towards them. They close their eyes and then the lights fully turn back on suddenly - everything is back as it was, with the desk in the original place. They fling themselves at the door again and manage to burst through it. Close up shot of them travelling through before a CCTV style shot reveals they're still in the same meeting room - nothing has changed. Cut to credits and then a shot of a laptop playing the CCTV style footage before a man closes it and walks away.