This essay contextualizes Nathaniel Mackey`s Song of the Andoumboulou within the topography of postmodern American poetry. In his seminal study of the postmodern series, Joseph M. Conte suggests that the series proceeds without looking back. Mackey, on the other hand, deliberately cultivates echoes, repetition, and recursivity in his serial work. The individual poems in Song of the Andoumboulou maintain a complex interrelation among themselves. The later poems draw out what was implicit, clarify what was inchoate, and qualify what was overly optimistic in the earlier poems. Formally, Mackey uses innovative techniques to create layers within individual Songs, incorporating gaps and breaks into their texture. A similar pursuit of incompleteness can be observed at various levels of his text, including his experiments with the book as a unit, anagrammatic wordplay, and his idiosyncratic use of the apostrophe. The cumulative effect of Mackey`s formal choices is the enlarging of seriality`s capacity for self-questioning and methodological doubt. It is therefore possible to see his work as both an exemplification and an extension of postmodern serial poetics.