Rising up from the Irish Sea lies the ancient kingdom of Mourne, a rural area in the east of Northern Ireland that teems with animal life. It's March and the start of the birthing season. The founder of the oldest veterinary practice in Downpatrick, Maurice King, receives a call about an extraordinarily rare birth on a farm he knows well. He heads straight out to check on the new arrivals. Also out on the road is vet Rachael Frew, Maurice's most experienced vet in the Downpatrick practice. Rachael gets an emergency call to a smallholding where a goat has been attacked by a donkey. Is it too late to save the goat's life? At the foot of the Mournes, in Newcastle, Maurice's son Cahir runs a smaller, sister practice. Cahir has an appointment with Boo, a pedigree bulldog whose owner would like her to breed. Boo has been unable to do so naturally, so bulldog Bailey has also been booked in to provide the semen that Cahir must collect to inseminate Boo.