A central question in Austronesian syntax concerns the nature of a typologically unusual four-way voice system found in Tagalog and similar languages. Drawing on previously overlooked binding facts, this paper demonstrates that Tagalog's four-way voice morphology is best analyzed as the spell-out of four bundles of abstract Agree relations that target the topic of a clause. Under the current view, Tagalog instantiates a discourse configurational language (Li & Thompson 1985; É. Kiss 1995; Miyagawa 2010) with accusative case alignment, featuring overt agreement with topics and not subjects.