Tree space is the vast mathematical terrain occupied by ancestral trees of a group of species. Between them, the trees—some bushy and some stark—account for all possible ways in which species might relate to one another. Maria McMillan’s first full collection creates a new, invigorating space in New Zealand poetry. These are poems that refuse to settle, that grow and climb fearlessly into unknowable places within science, personal history, politics, and ethics. Language breaks apart and fuses back together. Our edges blur with those of other species, creating a brilliant, shimmering cacophony.