The fourth season of All Creatures Great and Small will pick up in springtime of 1940 with change on the horizon for everyone in Skeldale House. James and Helen wonder when the right time might be to start a family, not knowing whether or not James will be called up to serve in the RAF. Tristan’s absence is felt by all, but no one more than Siegfried who attempts to hold the growing household, and himself, together as he braves this new world. Mrs Hall and Helen’s friendship blossoms as they look to the future and new trainee veterinary student Richard Carmody arrives, causing complications in the house.

Episode 1: High Castle
　　A university professor who had been working as a translator at the Nuremberg trials is stabbed to death. As Foyle investigates, he delves into the world of international oil politics and corrupt Nazi businessmen. Sam assists the murder inquiry by going undercover, despite her pregnancy.
　　Episode 2: Trespass
　　As Britain debates the creation of a Jewish state in Palestine, the son of a wealthy Jewish businessman is assaulted. The flames of anti-Semitism have recently been fanned in London by Charles Lucas, a right-wing writer, and Foyle suspects the attack was racially motivated.
　　Episode 3: Elise
　　After an attempt on Hilda Pierce's life, Foyle scrutinizes her work for SOE during the war. Could this be related to the deaths of nine SOE agents in France and rumors of a traitor called Plato?

Episode 1 - The Eternity Ring
　　MI5 suspects British atomic research has been infiltrated, and ask Foyle to investigate whether a Russian spy network could be at work in the heart of London.
　　Episode 2 - The Cage
　　Foyle’s investigation into the death of a nameless Russian leads to a mysterious military facility and the discovery that the victim was a spy with dangerous connections to British intelligence.
　　Episode 3 - Sunflower
　　Professor Peter Van Haren gives a lecture to a group of students on the self-portraits of the artist Rembrandt and causes a young man to suffer a frightening flashback which ends in tragedy.

讲述一个年轻兽医给乡间小动物们治病过程中发生的那些美好温情的故事。

这一季对应原著小说第九部和第十部，主人公乌特雷德将夺回祖传领地——贝班堡。