- The Post Office computer system is faulty.

- If you lose money, you repay it.

- The Post Office are suing us for 26,000 pounds.

(dramatic music) - This is the biggest miscarriage of justice in British history.

- It's the story of a bunch of little guys taking on one of the biggest government corporations.

- The gathering together of hundreds of subpostmasters to fight back against the Post Office's abhorrent behavior towards them.

- People don't really understand just how Machiavellian this was.

- Hundreds, if not now thousands of people had their lives ruined.

- Post Office Limited does not accept any of the allegations that are being made.

- The Post Office had invested a great deal of public money in a brand new computer system.

They would be adding all their stuff up at the end of the day, and it wasn't tallying.

These figures started getting completely out of hand.

They were told they were the only people having a problem.

- It can't be a system error because you're the only one.

And of course, they weren't the only one.

People found themselves in massive financial debt.

- [Julie] Hopes, savings down the pan.

- And every single one of them was innocent.

- To think that an organization could look at that body of people and think, "Yeah, they're all thieves."

- The Post Office lied to parliament.

- They knew that there was something wrong with my system.

- It's an underdog tale of strength, resilience, and a triumph of justice over this gross evil that's been inflicted upon them.

- The resilience and courage is really, really inspiring.

- I was very moved personally by the story.

You really get to the core of what they were going through as human beings.

- You really care for these people and the human relationships.

- [Patrick] It's still happening now and it's unresolved.

- I think it's absolutely fantastic that we're dramatizing it now so that people really understand what's going on.

- It's bringing the truth out.

- [Speaker] I'm really glad we're telling the story.

- [All] Yay!

- Finally, we'll get to know the whole truth.

(dramatic music)