"It's the summer of 2015, Brooklyn. The city is sweltering from another record-breaking heat wave, this one accompanied by biblical rains. Edith, a recently retired legal librarian, and her identical twin sister, Kat, a feckless romantic who's mistaken her own eccentricity for originality, discover something ominous in their hall closet: it seems to be phosphorescent, it's a mushroom ... and it's sprouting from their wall. Upstairs, their landlady,...