The Sheep Detectives

Outside the English village of Denbrook, shepherd George Hardy lives in a meadow and spends his time isolated from society, reading murder mystery novels to his flock of sheep. The sheep live in blissful ignorance, believing they turn into clouds upon death. When faced with an uncomfortable situation, they can will themselves to forget. They discriminate against a "winter lamb", born in winter rather than the typical spring. One morning, George is discovered dead outside his trailer. The town's only policeman, Tim Derry, initially thinks the cause of death is a heart attack. Reporter Elliot Matthews, in town to report on a local festival, believes it to be a murder, and encourages Tim to look deeper. Tim concludes George was poisoned by one of the townspeople. Devastated by George's death, the sheep decide to solve the mystery on their own. The investigation is led by the crime aficionado ewe Lily, the ram Mopple who always keeps his memories, and the loner Sebastian who George rescued from a carnival where he was being exploited.

During a will reading at the local inn, it is revealed that George had twins – a son and daughter – whose mother died in childbirth, and George, poor and young, decided to send them away for adoption via the church. The daughter, Rebecca Hampstead from the United States, reconnected with George and exchanged letters, and had just arrived in the country to visit him for the first time. Also in attendance are Tim; Lydia Harbottle, George's attorney; Reverend Hillcoate; butcher Ham Gilyard; innkeeper Beth Pennock; and neighboring shepherd Caleb Merrow. Elliot attempts to stay but is told to leave by Lydia, while she calls the son, Peter Van Vuren, who lives in South Africa to attend the event remotely via a phone call. During the reading, it is discovered that George was secretly worth a fortune due to him selling the patent for a sheep medicine that he invented for the treatment of orf. The new will awards this fortune to Rebecca, replacing an old will which donated the fortune.

After Cloud, a member of the flock, reveals she found one of Rebecca's silver bangles the night of the murder, contradicting her claim of not having met her father, the sheep lead Tim to the meadow where he finds the bangle. He also discovers the type of berry used to poison George squashed in the soles of her boots and of her name change and criminal history back in America. She is placed under arrest, with the motive of wanting the inheritance money. Although not entirely certain that Rebecca is guilty, Lily and Mopple, soon to be taken in by Caleb, decide to explore his meadow and meet their future flock mates, only to discover that Caleb has been collaborating with Ham to slaughter sheep for their lamb chop business, explaining why George frequently argued with him. They are soon chased by Caleb's German Shepherds, but Sebastian saves them, sacrificing his own life in the process. Lily realises that sheep do not become clouds upon death, and that she willed herself to forget every time a sheep close to her died.

She tries to lead the other sheep to safety, but Zora becomes terrified, willing herself and the other sheep to forget, much to Lily's dismay. Mopple tells her she must now embrace the memories of their deceased loved ones, instead of willing herself to forget. Feeling despondent, Lily tries to forget George, but with encouragement from his ghost, realizes that Rebecca is not actually the murderer, and has instead been framed by the real killer. She and Mopple recruit the small winter lamb to sneak inside the jail and paint a message with his hooves. The following morning, Tim sees a line of blue paint, then yellow, and then green from the mixing of both, on the floor.

Tim transfers Rebecca for prosecution. Immediately after, he notices the winter lamb, still with the paint on his hooves, and realises that Rebecca is innocent. In fact, none of the named parties in direct attendance at the will reading were actually George's killer. With help from the sheep, he recalls one of George's hands was stained green, and this was due to the mixing of blue, from the medicine he fed the sheep, with yellow, from the blond hair dye of the perpetrator. Additionally, the suspicious new will seemingly gave a motive to Rebecca, but actually gave a motive to her twin brother Peter, who would now inherit the money as next-of-kin if Rebecca was convicted. Peter has an ironclad alibi; he is in South Africa and not in town at all. Tim concludes that "Elliot Matthews" is actually Peter himself, with dyed blond hair to avoid the family resemblance, and that he planted the false new will and framed his sister in order to inherit his father's fortune, rather than see it given away.

Exposed, Peter attempts escape but is thwarted by twin rams Reggie and Ronnie. He is arrested for his crimes, while Rebecca is released. It is revealed that Rebecca's mother was named Lily, and Rebecca takes her father's surname as well as ownership of the meadow and George's sheep. She also buys Caleb's sheep, allowing them to avoid Ham's meat business. She sits down to read George's guide to raising sheep to her new flock. Lily names the winter lamb George and welcomes him into the flock, becoming the lamb's mother figure, as a cloud resembling Sebastian watches over the land.