Polish immigrant Karol Karol finds himself out of a marriage, a job and a country when his French wife, Dominique, divorces him after six months due to his impotence. Forced to leave France after losing the business they jointly owned, Karol enlists fellow Polish expatriate Mikołaj to smuggle him back to their homeland.
A young, idealist American gets a job as a train conductor for the Zentropa railway network in postwar, US-occupied Frankfurt. As various people try to take advantage of him, he soon finds his position politically sensitive, and gets caught up in a whirlpool of conspiracies and Nazi sympathisers.
Krzysztof, a semantics professor and computer hobbyist, is raising his young son, Paweł, to look to science for answers, while Irena, Paweł’s aunt, lives a life rooted in faith. Over the course of one day, both adults are forced to question their belief systems.
