Susan Howe's newest book of poetry is a revelation as well as a mystery.

"What treasures of knowledge we cluster around." That This is a collection in three pieces. "Disappearance Approach," an essay about Howe's husband's sudden death—"land of darkness or darkness itself you shadow mouth"—begins the book with paintings by Poussin, an autopsy, Sarah Edwards and her sister-in-law Hannah, phantoms, and elusive remnants. "Frolic Architecture," the second section—inspired by visits to the vast 18th-century Jonathan Edwards archives at the Beinecke and accompanied by six photograms by James Welling—presents hauntingly lovely, oblique type-collages of Hannah Edwards Wetmore's diary entries that Howe (with scissors, "invisible" Scotch Tape, and a Canon copier) has twisted, flattened, and snipped into inscapes of force. The final section, "That This," delivers beautiful short squares of verse that might look at home in a hymnal, with their orderly appearance packing startling power:

That this book is a history of
a shadow that is a shadow of


Me mystically one in another
another another to subserve.