QUALITY documentaries should unfold with the delight of opening a Christmas present.

You want to find out what is in the package or in the box as fast as you can but you know the small wait will make the surprise even greater once it is opened.

This is the case with 'The Radical Story of Patty Hearst' which started on PBS America on Saturday, February 2.

This was the first in a six parter which will shed more light on what the blurb for the series states: "Follows Patty’s incredible story, from her kidnapping (by the Symbionese Liberation Army) to life on the run as an armed revolutionary, her subsequent imprisonment – and eventual pardon.

If you know nothing about Patty Hearst then you will enjoy the story which has more twists than the seven headed snake which was the symbol of the Symbionese Liberation Army.

It is as they say a 'cracking tale'.

I have seen another documentary about Patty Hearst, but I am enjoying this as it is taking its time and showing you the different layers of what might first appear a very strange case.

What we see in the incredible story of Patty Hearst, the granddaughter of American publishing magnate William Randolph Hearst, who is the closest thing to 'An American Aristocracy' turn into bank robber and guerilla prepared to fight (with a gun) the system of law and order.

The first episode lays the ground. It tells you about Patty Hearst, her up bringing, where she stood in society, about her parents, explains all about the Symbionese Liberation Army and why she was kidnapped.

We hear from her former fiancé, Steven Weed about the night both of them thought they were being robbed in their apartment in Berkeley but it turned out to be a kidnapping.

There is also an interview with one of the members of the Symbionese Liberation Army who carried out the kidnapping.

It is powerful stuff. You are hooked from the start. Once the documentary begins you are on the ride. It might start slowly but from now on it will be a white knuckle, finger gripping, tension rollercoaster.

Best thing is to sit back, strap yourself in and go with it. By the end of this tale from the 1970s you will be glad you watched this documentary.

PBS America can be found on Freeview 94, Freesat 155, Virgin Media 276, Sky channel 160 and now its new on demand channel on Amazon UK.