松鼠塞利和他的小伙伴们遇到了新的威胁，邪恶的市长要拆掉公园建筑游乐场，塞利这次必须团结起来拯救家园。

炎热的夏天过去，枝上的树叶慢慢转成红色。中央公园内，松鼠、浣熊们发现过冬的坚果根本不够用，这群小动物可能面临一场前所未有的饥荒。松鼠塞利（威尔·阿奈特 Will Arnett 配音）和安迪（凯瑟琳·海格尔 Katherine Heigl 配音）奉命前去寻找坚果，它们计划打劫一辆坚果车，谁知却造成了一场大混乱，还导致好不容易的手的坚果毁于大火。在此之后，塞利遭到流放，只有他的老鼠朋友巴蒂（Robert Tinkler 配音）自始至终跟着他。另一方面，安迪则和自我感觉良好的同伴格里森踏上寻找坚果的征途。最终，安迪和塞利在一座库藏丰富的坚果店重逢，而那里的幕后老板竟然是一个臭名昭著、穷凶极恶的罪犯。 　　螳螂捕蝉，黄雀在后，犯罪分子策划新的劫案同时，却不知有一群小动物正准备打劫他们。

After breaking out of a rehabilitation zoo, Frankie, a squirrel with all the angles, returns to his forest. He learns from his dim-witted best friend, Cody, a porcupine and street-con, that while he was in lock-up, the entire forest was picked clean by The A.C.O.R.N.S. Institute (Alternative Cosmetic Oils for Regenerative Natural Skin-care). No acorn was left behind. With winter just around the corner, it's a potentially devastating blow to all forest critters. So, Frankie has no choice but to bust into the brand new, state-of-the-art, rodent-proof A.C.O.R.N.S. Processing Plant and take back all of the acorns! Though a seemingly impossible heist, success would not only save the lives of his forest friends, but it would also give Frankie a chance to win back the love of his life, Lola, a local "show squirrel." Sadly, Lola has been burnt by too many of Frankie's false promises in the past.

When Petra spends an evening with her best friend Sanna, Sanna asks how she knew she was bi. Petra tries in earnest to show her the truth.