故事开始于1940年春天，Skeldale House的每个人都面临改变。James和Helen在考虑何时适合组建家庭，同时担忧James是否会被征召加入皇家空军。Tristan的离开让所有人感到失落，尤其是Siegfried，他努力维持这个不断变化的家庭，也试图让自己适应这个新世界。Hall夫人与Helen的友谊愈发深厚，她们展望未来。而新来的兽医实习生Richard Carmody的到来，则为这个家庭增添了新的复杂局面。

第3季始于1939年春天，James和Helen正准备步入婚姻殿堂。James要面对新婚生活以及事业中的新责任，而Helen则需适应放下过去的挑战。Tristan终于通过了考试，开始以正式兽医的身份迎接新生活。Hall夫人或许准备敞开心扉，追求家庭之外的情感。而在战争阴云笼罩下，Siegfried不得不直面第一次世界大战带来的痛苦回忆。

Channel 5和PBS Masterpiece宣布一次性续订《万物生灵》第五季、第六季，均由6集和圣诞特别集组成。

Based on Ann Ming’s book For the Love of Julie, the series tells the heart-breaking story of Ming’s 15-year-long battle for her daughter Julie’s murderer to face justice. Ming’s daughter was found in the bathroom of her house in 1990, 80 days after she had disappeared, and the man who killed her was twice acquitted following mistrials before eventually admitting to the murder. The archaic double jeopardy law meant he couldn’t be tried twice for the same crime and it is this law that Ming and her family successfully overturned.