Nofel iasoer ar gyfer yr arddegau, wedi'i lleoli mewn tref fechan ar arfordir Gwynedd Pur anaml y ceir Nadolig gwyn yno gan fod y dref mor agos i'r m??r Ond eleni, daw'r eira yn annisgwyl cyn i neb fedru dianc o'r dref Enillydd Gwobr Tir na n-Og 2008 [A spine-chilling novel for teenagers, set in a small coastal town in Gwynedd They never have a white Christmas as it's so close to the sea But this year, the snow comes suddenly before anyone has a chance to escape Winner of the Welsh Tir na n-Og Award 2008]