Based on a true story dating back to 1985 when two Polish boys, a teenager and his little brother, escaped from communist Poland all the way to Sweden, hidden under a truck. In the movie, their destination has been changed to Denmark.

八岁的巴伯家门前有一个小湖，冬天他喜欢在那里滑冰。但冰的厚度是不一定的，只有厚到一定程度才可以在冰面上安全地玩耍。巴伯的爸爸是一位数学家，精通电脑，相信一切都能够用电脑方程式运算出来，比如门前小湖的冰面厚度就可这样算出。圣诞节前，小巴伯想去滑冰，他按照爸爸的教导打开电脑询问计算结果，电脑说，“I am ready. ”于是他穿上爸爸给他的圣诞礼物冰鞋，上了冰面。正当他欢快玩耍的时候，湖上的冰破了，巴伯葬身湖底。