姐妹:監禁的回憶

　　Anna is stuck: she's approaching 30, living like a hermit in her mum's garden shed and wondering why the suffragettes ever bothered. She spends her days making videos using her thumbs as actors - thumbs that bicker about things like whether Yogi Bear is a moral or existential nihilist. But Anna doesn't show these videos to anyone and no one knows what they are for. A week before her birthday her Mum serves her an ultimatum - she needs to move out of the shed, get a haircut that doesn't put her gender in question and stop dressing like a homeless teenager. Naturally, Anna tells her Mum to "back the f-off". However, when her school friend comes to visit, Anna's self-imposed isolation becomes impossible to maintain. Soon she is entangled with a troubled eight year old boy obsessed with Westerns, and the local estate agent whose awkward interpersonal skills continually undermine his attempts to seduce her.

　　馬丁（Michael J. Fox 飾）才回到現實世界與女友團聚，布朗博士（Christopher Lloyd 飾）就心急火燎地把他們帶到了30年后的未來世界，原來這一次是馬丁未來的兩個孩子因參與搶劫鋃鐺入獄，博士要攜馬丁一起阻止悲劇發生。　　周旋一番后，兩個孩子被成功挽救，但三人回到現實世界后，卻發現周遭發生了天翻地覆的變化，世界被貝夫（Thomas F. Wilson飾）所控制，馬丁的父親喬治慘死，母親洛蓮（Lea Thompson 飾）竟然成了貝夫的妻子！　　這一切都是因為時光機器的秘密不慎被未來的老貝夫識破，他偷偷回去搗鬼，竟因此使得整個世界都在他的掌握下！馬丁與博士再次踏上時光穿梭的征途，希望將世界扳回正軌。

瑪吉驚訝地發現一名自稱已與丈夫艾倫結婚的女子。起初是對手，但他們很快就發現了圍繞艾倫和他之前欺騙的許多妻子的謊言網。

幽靈們被艾莉森體貼的慷慨感動了，于是決定給她一份特別的圣誕禮物作為回報——但艾莉森幾小時后就要回來了，他們能及時完成這個雄心勃勃的計劃嗎?