A collection in five parts, Susan Howe’s electrifying new book opens with a preface by the poet that lays out some of Debths’ inspirations: the art of Paul Thek, the Isabella Stewart Gardner collection, and early American writings; and in it she also addresses memory’s threads and galaxies, “the rule of remoteness,” and “the luminous story surrounding all things noumenal.” Following the preface are four sections of poetry: “Titian Air Vent,” “Tom Tit Tot” (her newest collage poems), “Periscope,” and “Debths.” As always with Howe, Debths brings “a not-being-in-the-no.”