马库斯(Richard Gibson 饰)邀请自己的同学兼好友雷欧(多米尼克·格尔德Dominic Guard 饰)到自己家去玩,就这样,雷欧结识了马库斯的姐姐玛丽安(朱莉·克里斯蒂 Julie Christie 饰),美丽又善良的玛丽安给雷欧留下了非常深刻的印象。马库斯得了传染病,没办法陪雷欧玩了,雷欧就此结识了名为泰德(阿兰·贝茨 Alan Bates 饰)的农夫,泰德拜托雷欧帮他送信给玛丽安,雷欧答应了他。 之后,雷欧和退伍军人修斯(爱德华·福克斯 Edward Fox 饰)交上了朋友,并且震惊的得知,玛丽安的家人准备将她许配给修斯,不仅如此,雷欧还意外的发现,自己帮泰德和玛丽安送的那些信件,其实是他们的情书。Summer 1900: Queen Victoria's last and the summer Leo turns 13. He's the guest of Marcus, a wealthy classmate, at a grand home in rural Norfolk. Leo is befriended by Marian, Marcus's twenty-something sister, a beauty about to be engaged to Hugh, a viscount and good fellow. Marian buys Leo a forest-green suit, takes him on walks, and asks him to carry messages to and from their neighbor, Ted Burgess, a bit of a rake. Leo is soon dissembling, realizes he's betraying Hugh, but continues as the go-between nonetheless, asking adults naive questions about the attractions of men and women. Can an affair between neighbors stay secret for long? And how does innocence end?