The Blue Pill.

[BIAD]

...It worked in a similar way here, back in the day. The company owned everything, and did it's best to own the miners, too.
They didn't pay with real money, they paid in "scrip" - company owned and produced faux money that could only be spent
at the company store...

That reminds me, after the tour around the caves, there was the opportunity to trade your current currency
for old pennies of that time and send them in an old store and pub. I found it odd at the time that these two
buildings were the only other structures on the slate mine's property and seemed to have no connection to
it.
Now I know.

Cheers Ninurta.