For many years now, Gwilym Puw has been working as a school inspector, and is well aware of the terrible anxiety that strikes the heart of every teacher as they await a visit from him and his compatriots on the 'Gorestyn' team. However, one day Gwilym starts to see the world through a different lens – which causes him to question everything...

Mae Gwilym Puw yn gweithio (ers blynyddoedd, bellach) fel swyddog arolygu ysgolion, ac yn hen gyfarwydd â'r anesmwythdra dybryd a gyneuir yng nghalon pob athro o glywed am ymweliad ganddo ef a'i gyfoedion o dîm 'Gorestyn'. Fodd bynnag, un diwrnod mae Gwilym yn dechrau gweld y byd drwy lens gwahanol, rywsut - sy'n peri iddo gwestiynu popeth...