"An Unexpected Kinjutsu!!" (まさかの禁術!!, Masaka no Kinjutsu!!, Viz: Forbidden Jutsu Shock!!) is chapter 510 of the original Naruto manga.
Tobi falls into the chasm, and Konan continuously detonates exploding tags for ten minutes. Tobi survives, and states that he used Izanagi to escape from her attack. After Tobi explains how Izanagi works, Konan tries to kill him. Her attack is interrupted by Tobi, and he uses a genjutsu to force her to reveal the location of Nagato's corpse. Tobi then arrives at the shrine where Nagato is buried, and states that Nagato is the "third of the six paths" and a member of the Uzumaki clan.