This is the BBC.

This is the Rat Line, a new series from the BBC.

It's about Nazis, spies, love, death, secrets and liars, and a family called The Vectors.

Spring 1942, Austria.

The Baroness and her six children are at their summer house in Zelle Amze,

in a delicate lakeside town near Salzburg.

They're bronzing themselves in the mountain sun, boating, frollicking in the low.

She writes to our husband the children of Thrivegan, and becoming strong swimmers.

Swimming is important in this story.

The Baron can't be with them this summer.

It's a shame, but he's much too occupied with his work, 700 miles away, in a place called Lemberg.

In a letter to his wife, he writes, there's a lot going on in Lemberg.

He just doesn't have time to join his family, not right now anyway.

There is indeed a lot going on in Lemberg.

Over the course of four months in 1942, Lemberg's Jewish population was steadily, swiftly and ruthlessly liquidated.

Shot, hanged or sent to Belzec, a nearby extermination camp, where they were gassed.

I've got a certain interest in these events, because my work as a barrister involves me in many cases of mass killing,

but also for another reason.

My grandfather, Lyon's entire family, were all wiped out.

Whilst the Bounders and the children were relaxing by the lake, my grandfather's family were being murdered.

This is a story about the Baron.

A man called Otto von Vechter.

...