Poet Simon Armitage goes on the trail of one of the jewels in the crown of British poetry, Sir Gawain and the Green Knight, written about 600 years ago by an unknown author. The poem has got just about everything - it is an action-packed adventure, a ghost story, a steamy romance, a morality tale and the world's first eco-poem. Armitage follows in the footsteps of the poem's hero, Gawain, through some of Britain's most beautiful and mystical landscapes and reveals why an absurd tale of a knight beheading a green giant is as relevant and compelling today as when it was written.