Copenhagen by Michael Frayn is based upon historical events and persons. Frayn is writing about the visit Werner Heisenberg made to the home of Neil Bohr and his wife Margrethe in Copenhagen in 1941. Making his characters and events as historically accurate as possible, he takes a historian's approach to theater. Each of the characters speak often in words which are direct quotes of their real namesake. Frayn is trying to preserve the integrity of historical events in order to bend time a little bit. The entire play takes place in an impossible gap between life and death and whatever lies beyond death, all of the characters being dead already. They stand around discussing Heisenberg's purpose in the 1941 visit as well as the consequences of that time, along with countless iterations of the event. They are trying to determine what responsibility each of them have in the development of the atom bomb.
Although terribly experimental, Frayn is really not doing anything revolutionary in this book. He's basically sensationalizing a history lecture through narrative. He runs through all the possibilities and consequences of Heisenberg and Bohr's actions, not so much in the interests of laying blame but in order to trace the threads of action which tie different actions together. His cause is the same as any historian -- to understand why events in human history transpired the way they did and what the consequences of those events are for us today. In the play, Frayn is able to really dive in and manipulate the timelines in order to arrive at new conclusions from new perspectives.
Each of the characters are suffering from guilt. They can't find peace in their deaths, so they're trying to sort through what went wrong. More importantly, they're trying to find peace. After seemingly endless abstract discussions about Copenhagen they finally conclude that the development of the atomic bomb was inevitable. They cannot dwell upon the past forever because it's past. While they all certainly played a role in some tragic historical events, they already participated. The future has yet to occur, so that's the thing to be really concerned about. In a very real sense, Heisenberg and the Bohrs are able to work through their guilt by processing. Like playing chess, they argue until they have placed all the pieces in perspective. From a totally accurate point of view they are able to take an appropriate amount of responsibility and move on from the events of their lives.
