Catherine Leroux’s The Party Wall shifts between and ties together stories about pairs joined in surprising ways. A woman learns that she may not be the biological mother of her own son despite having given birth to him; a brother and sister unite, as their mother dies, to search for their long-lost father; two young sisters take a detour home, unaware of the tragedy that awaits; and a political couple—when the husband accedes to power in a post-apocalyptic future state—is shaken by the revelation of their own shared, if equally unknown, history.