故事讲述马库斯的妻子在一场悲剧的火车事故中身亡，马库斯要赶回家陪女儿玛蒂尔德。这场事故似乎是一场意外，但一位数学极客，也是火车中的一位乘客，与他的两个同事现身，说出他们确信这场事故背后另有隐情。...

　　Kauffmann, who was the Danish ambassador to Washington in 1939 when World War II started and who declared himself to be the only true representative of a free Denmark in opposition to the Nazis...