The most significant dramatic device used in Harold Pinter's Betrayal is his use of reverse chronological order. Of course this is not the traditional way a play or story unfolds, so his choice deserves some attention.
A traditional story unfolds, from beginning to end, and we are along for the journey. We watch, follow, and listen, and we live the experiences as they happen to the characters. When something happens in the present, we do not have any real sense of how that action, conversation, or response is going to impact the characters or situation in the future. A careless word or incident today might turn out to be a turning point in a relationship or the cause of a tragic fall, but we do not know it yet.
In this story, we know the end at the beginning. This gives us a complete awareness of how the story ends, and the going back allows us to see, step by painful step, exactly how that ending happened. We see things with foresight instead of hindsight.
Not surprisingly, this play centers around the theme of betrayal. The story begins with three ruined relationships between the three primary characters: Robert, Emma, and Jerry. The first scene occurs in 1977 after the affair between Jerry and Emma has ended, and the final scene in the play takes place in 1968 when the affair begins. In between are some of the significant moments which helped cause the pain we discover at the beginning of the play (the end of the relationships).
We meet Jerry and Emma first as they meet for an awkward drink at the end of their long-term affair. Every one of the three main characters has violated trust in one way or another. At this point, none of the characters is happy. As the play continues, we learn that this has not always been the case, and we see how small moments and seemingly insignificant things contributed to the final heartbreak we saw at the beginning of the play.
For example, in scene two we learn that Robert knew about the affair between his wife and his friend for years but did nothing about it. Obviously he did not care enough to take action. As we go backward in time to scene three, we see that the affair between Emma and Jerry ended with a whimper, as well.
Even farther back in time, we are privy to the simple moments of revelation which created significant pain, such as the letter to Emma from Jerry which Robert reads in Venice, making Robert wonder if he is even the father to his son, Ned.
The farther back in time the characters go, the more painful such small things become. In the end, we learn that Jerry was Robert's "best man" and was making a play for his best friend's wife even on their wedding night.
The journey from that drunken kiss on Emma and Robert's wedding night is a slow torture of deception and betrayal. If the story had been told in a more traditional chronological order, we would not know the significance of each small action and detail on the end of the story. As written, however, the emotional impact of each word and incident takes on the weight of the ending. These details contribute to the significance and pain of each betrayal.
Movie critic Roger Ebert says this about the unique structure of this play:
The "Betrayal" structure strips away all artifice. It shows, heartlessly, that the very capacity for love itself is sometimes based on betraying not only other loved ones, but even ourselves.
Pinter's innovative use of reverse chronology enhances the impact of each moment of betrayal. We feel each betrayal more deeply.