The mood of the novel is tense. While Van describes the Herlandians' society with wonder, underlying this wonder is always the sense that things will eventually come to a head. After all, the men are essentially prisoners who must negotiate a way to return home. One moment where the tension is palpable is in Chapter 10, when Van mentions that the men have been lying by omission about their homeland:
None of us were willing to tell the women of Herland about the evils of our own beloved land. It was all very well for us to assume them to be necessary and essential, and to criticize—strictly among ourselves—their all-too-perfect civilization, but when it came to telling them about the failures and wastes of our own, we never could bring ourselves to do it.
The men are all trying to marry Herlandians, and they want to bring their wives back with them. At first, they may not have gone into detail about all the "evils" of home because they wanted to present the positives first. But as time has gone on, they have all started to feel the omission hovering over them. Eventually the women will find out the truth, either when the men tell them or when they see the outside world for themselves. And it is undeniable that the women can be dangerous when they want to be. Despite the ostensible cooperation between the men and their tutors, and between the men and their prospective wives, the "Colonels" have always held the upper hand. Making them angry could result in dire consequences for the men.
The tension Gilman creates for her characters mimics the tension women and marginalized people experience on an everyday basis. For the first time, Van, Jeff, and Terry's gender is a liability for them. They have to worry about the anger of the people in power in a way men (at least white men like Gilman's main characters) rarely do. While Gilman wants her readers to marvel at the society the Herlandians have created, she also invites them to imagine a world in which men must think about the consequences of their actions.
