Missing cog?

[Bulbatron]

Thanks for getting back to me. I don't think reloading will be an option since my last save from before I ever entered the machine room no longer seems to be there. I'm assuming from this that only a certain number of previous auto-saves are kept before the computer starts overwriting them. I've left, re-entered and saved in, the machine room several times now, hoping the last cog would appear.

At one point I even took all the moveable objects out of the rooms and stored them in the corners of the corridor to try and clear the rooms in case the objects were hiding a cog, but no luck.

I will of course, have another look, concentrating on the areas you suggested. I really hope you're right. If not, it looks like it might already be game over for me.