One Piece Collection 18 contains episodes 422-445 of the anime directed by Hiroaki Miyamoto.
Luffy and Hancock arrive at the underwater prison of Impel Down, where the Snake Princess uses every ounce of her beguiling charm to smuggle him past the guards. Once inside, unexpected alliances help Luffy survive the increasingly dangerous levels of the prison. At the depths of it all lies the poisonous Warden Magellan whose toxins put the rubber-mans life at stake.
Its up to his new allies to save him by tracking down a miracle worker rumored to have vanished into the gates of hell. Enter Ivankov. This larger-than-life personality has the Healing Hormones needed to save Luffy, but the cure could take years off the pirates life! With his brother just beyond reach, Luffy must take the ultimate leap of faith before its too late.
Special Features:Episode 425 Commentary, Episode 432 Commentary, Episode 434 Commentary, Episode 442 Commentary, Chopper Plays Doctor, Cooking with Sanji, Textless Opening Songs, Trailers.