In the post-apocalyptic world there are three species of beings: The first are humans, who populate the earth in various cities and hide behind the Vatican for protection—protection against the Methuselah, commonly known as vampires.  Vampires are found nestled in human populations or in their capital. Just as Methuselah feed upon the blood of humans the third feeds on the blood of vampires. The third, Crusniks, are rare, immortal and all-powerful beings. Trinity Blood follows one Crusnik’s path to redemption for sins committed 900 years in the past.