The Sword of John the Revelator is an object in DEXTER. The weapon is an ancient artifact that is believed to have belonged to John the Revelator, the man responsible for writing the Book of Revelation. Through the years this blade comes into possession of the University of Tallahassee, where a Professor James Gellar presides as a teacher in religious studies. The sword itself is a rust-stained iron gladius with a golden handle and grip, with slight indentions on both sides of the edge.
One of Professor Gellar's former students, Travis Marshall, steals the sword in early 2008 before approaching Gellar with the claim that they are both the Two Witnesses. Professor Gellar loses his job, now blamed for stealing the artifact from University and is faced with the delusional Travis. Shortly thereafter Travis, claiming that he can prove their inability to die, pierces Gellar's chest with the blade stabbing him directly in the heart thus killing him. He proceeds to lock the body away in a freezer and shuts out the memory, believing that his professor was still alive as the second witness.
The Sword is currently in Travis's possession and has been used in the Doomsday Tableaus as he tries to bring about the End of Days. So far the sword has been used to strike and kill Omar Rivera, Nathan Roberts and possibly both Lisa Marshall and Trent Casey.