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.

第三季故事从1939年春季讲起，第二次世界大战即将到来，镇上的居民都将面临各种变化，特别是对James和Helen而言。两人的生活步入了新阶段，而他们周围的世界正走向一个充满不确定性的时期。

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。