Martha Collins offers haunting reflections on time and other subjects in Day unto Day, a spare and subtle seventh collection. The book consists of six sequences: during one month each year, for six years, Collins wrote a short poem each day. With perfectly distilled lines, she captures the aching, liminal beauty of one day becoming another -- the slow burn of time passing, the ambiguity of an "old / new leaf" turning over, even as she collages a wide range of material that includes often disturbing news of the world. Writing in the tradition of poetic meditation, Collins shows us the full degree of her mastery -- a mature voice, poems with tremendous scope, and lines exceptionally controlled. Here is the work of a seasoned poet at the height of her career.