This paper examines the post (and still ongoing) society of the cataclysmic era and its situational existence in John Lancaster’s The Wall, which depicts dystopia due to rising sea levels and climate change. The word “situational” is used for those who do not have regular places for themselves and who are likely to be deprived at any time but unlikely to have recoverability in their territories. As Amitav Ghosh pointed out, climate change is an unintended result of humans as a species, and different human groups have contributed to climate change in various ways, but global warming is ultimately the total result of all human actions over a long period. The novel correlates Brexit, which means building a fortress on Britain’s island, defending the wall, preventing refugees by making self-isolation choices, and not engaging in relief work on what has not happened in their territories. In the words of Bruno Latour, the New Climate Regime has long swept the border, exposed us to all the storms, and no wall we can build will stop the invaders. In other words, border closures to confront refugees on two legs cannot be limited to countries such as climate, erosion, pollution, resource depletion, and habitat destruction, and they cannot prevent shapeless movements. In this paper, I will contemplate the ‘between-difference’ of various ‘us’ in The Wall, Gosh’s ‘us’ and Latour’s ‘us’ and examine the real alternative possibility of the ‘floating community’ in addition to non-human activities such as cold, wind and typhoon represented in the novel.