Mae'r Nadolig yn agosau, ac mae trigolion Graig yn hel celc ar gyfer y dathliadau. Ond mae rhyw ddihirod ar waith yn y gymuned, a'u hanfadwaith yn bygwth chwalu'r cynlluniau am Nadolig llawen a gwlyb.Ac mae si ar led fod rhywun go enwog wedi prynu tafarn y Brithyll Brown.Comedi dywyll yw Crawia - trydedd nofel Dewi Prysor, a dilyniant i Brithyll a Madarch.
Dewi Prysor Williams, or Dewi Prysor as he is more commonly known, is a Welsh author and musician. He was born in Dolgellau in 1967 and raised in Cwm Prysor, near Trawsfynydd. He lives in Llan Ffestiniog with his wife and three sons.
In 1992, Prysor was accused of 'conspiring to cause explosions' as part of the Meibion Glyndŵr arson campaign. He spent 14 months in Walton Prispon, Liverpool, while awaiting a trial. He was found not guilty. He subsequently wrote a drama based on this experience called DW2416, which was performed 25 times on tour by Llwyfan Gogledd Cymru/North Wales Stage.