Each production of Cloud 9 has the liberty to choose its own character doublings, which can and does result in drastically different interpretations of the second act. Perhaps the greatest of these decisions is who will play Cathy. Logistically, there are really only two possibilities: either Clive or Joshua can become Cathy. Caryl Churchill admits an affinity for the Clive-Cathy swap, and, indeed, this combination seems to make the most sense thematically. If Clive becomes Cathy, the first image presented in the second act is one of the first act's aristocrat rendered childlike by the passage of time. Churchill intends for Cathy to stand out, making her the only character in the second act played by a member of the opposite sex.

Churchill's choices in switching roles say certain things about how time has treated her protagonists. Without any words being exchanged, an audience can make some assumptions about where the story stands as Act II begins. Victoria is an actor now, no longer a doll, suggesting that she has acquired at least some independence from her father's control. Betty and Edward are now played by same- sex actors, indicating that they, too, might have come closer to finding out who they truly are. One must be careful about drawing too many conclusions, however, because each production has some liberty to choose its own casting switches, a convention that allows for different interpretations of the second act's opening images.

Perhaps the most notable change marked by the opening of the second act is the shift in tone. Churchill lets the audience know immediately that this will not be the farce that the first act was. The characters speak without stereotypical speech. Their language is less theatrical and more conversational. Instead of making poetic statements about the nature of women and the need to tame the natives, as Clive was so inclined to do, Lin and Cathy speak about movies and Betty speaks about the weather. Churchill has not robbed this new act of comedy, but she has made it possible for the audience to really identify with the protagonists. When Churchill wrote the play, the second act was meant to take place in the present day. In some ways, the second act brings the lessons of the first act to bear on the present audience.

Regardless of which actor plays Betty in the second act, the character Betty exhibits remarkable change. She speaks almost to exhaustion, far more opinionated than her first act counterpart. She also announces her intention to leave Clive, laying out her intention to give independence, and even work, a try. Nevertheless, Betty is not fully separated from her past. She still speaks of Africa with nostalgia and favors Victoria's arguably traditional relationship with Martin.

Like Betty, Edward and Victoria are not fully capable of leaving the past behind. Edward is still uncomfortable about his sexuality, becoming embarrassed when Lin asks him about it, and both Edward and Victoria acknowledge the difficulty that will come from a separation between their mother and father. In some ways, in fact, Betty's age and naiveté make her less afraid of starting over in a more liberal setting. As Edward and Victoria resist fully committing to their new identities, Betty remarks, "I'm finding a little flat, that will be fun." This first scene marks the juxtaposition between old and new in which Churchill quickly introduces the problems of the transition from one to the other. She throws Betty, Edward, and Victoria into Lin's new London and forces them to deal with new sexual and political freedoms.