Dyffryn bendithion daw: … a beautiful valley in Wales, loved by Llywelyn, where he has lived and farmed all his life, but is now losing possession. It has been taken for a reservoir. He has fought all he can, but to no avail, and lost his wife and son in the process. He may also be losing his mind.
Nerys, Llywelyn’s daughter, feels alone and isolated, caring for her young son Davie, trying to bring her father out of his stupor. Iolo, father of Davie, a dark violent man just out of prison, wants to renew their relationship but she resists. He constantly urges Llywelyn to extreme action against the reservoir construction. Spicer, overseeing the reservoir build, is growing increasingly frustrated. The construction is beset by problems and delays, his bosses are on his back and he desperately needs to find quick solutions. Into this mix stumbles Howard, a PHD student studying mosses. Nerys falls for him, so different to the local men. Iolo glowers and threatens while Howard wants Chrissie, who lives with her activist husband on a nearby commune.
Reservoir workers and local villagers all add to the explosive mix as the reservoir nears completion and emotions and actions escalate. Love, passion, anger, hate, struggle and tragedy; all in this isolated corner of rural Wales. And little lambs too.