[4][5] Based on the life of Ellis Humphrey Evans (Huw Garmon), killed in the First World War, the cinematography starkly contrasts the lyrical beauty of the poet's native Meirionnydd with the bombed-out horrors of Passchendaele.

[2][6] As a farmer's son in the village of Trawsfynydd, Ellis Humphrey Evans composes poetry for local eisteddfodau under the bardic name Hedd Wyn ("Blessed Peace"), dreaming of being crowned Chief Bard at the National Eisteddfod.

When, in August 1914, Britain declares war on Germany, several young men from Trawsfynydd join the British Army, including Ellis' friend Griff.

Facing what may be his last chance to win the Eisteddfod, Ellis pleads with his platoon commander to send his awdl Yr Arwr (The Hero) via the Army Postal Service.

Hedd Wyn has been cited by Kate Woodward of Aberystwyth University as one of "a number of films produced for S4C which ... scrutinized the trinity of dynamic tensions that existed between Wales, England and 'Britain'".