SLASH! A man’s hand is sliced off during an attempted rape in a dark alley. CHOP! The unseen sword-wielding assailant swings down mightily to sever his prey straight down the center, splitting him in two. Can’t you just hear Castle saying something like, “This guy’s half the man he used to be?”

The dead man is an ex-con named Tyler Faris. He recently got into an altercation with mob man Tony “The Butcher” Valtini, who says Faris was likely killed by the same vigilante who attacked him with a sword. Tony shows the L-shaped scar that was left on his butt cheek. Surveillance footage shows the attacker wearing a slick red costume and mask. Castle is positively giddy. He exclaims, “Our killer is a superhero!”

Castle shows Beckett video footage of the Red Maroon, a wannabe superhero who is proof that subculture of real-life crusaders exists. They check out the one place any true collector of comic books is sure to frequent: Comicadia. The store even sells Castle’s Deadly Storm graphic novel. More importantly, the shop owner recognizes the costume the killer wore. It matches the one seen in a comic titled “Sword of Lone Vengeance.”

The Lone Vengeance character was created by a guy named Sean Elt. The comic hero’s suit features a knuckle-plate that Castle remembers seeing at the crime scene. Sure enough, the evidence is on the ground in the alley. Too bad Lone Vengeance swoops in to snag the knuckle-plate while making a clean getaway. Fortunately, Esposito now knows this particular superhero’s secret identity.