It's a sweltering summer's day in 1998.

Two couples stand side by side on a doorstep.

They may never have met, if not for a few tattie pieces of paper that brought them together.

There is only one subject of conversation, the inked forgery in front of

them and its horrifying consequences. I'm Hannah Fry, a mathematician who studies patterns in

human behaviour, and from BBC Radio 4, this is uncharted, tales of data and discovery.

This is a series about how numbers and graphs can help you to map the invisible,

about how plots can be rich with hidden depths and unheard stories,

and about how sometimes, if you know where to look, there is mystery and drama and intrigue to be found, all concealed within a few simple lines on a page.

Angela Woodruff was at home in a small village in Warwickshire, a beautiful old stone building with hysteria covering the walls.

It had been two weeks since her mother's death, when her life was punctured by an unexpected phone call.

It was strange news.

A will had been discovered by a solicitor almost a hundred miles away,

and it was coming through on the fax machine.

Examining it carefully, Angela turned the document over in her hands

and was stunned by what she read next.

It was a strange day. Angela phoned me at work and she was horrified by this document.

It was the will.

And Angela, she... I think she was so upset

that she couldn't bring herself

to confront the idea of what was involved in pursuing it.

That is the voice of Angela's husband, Phil Woodruff.

...