Last night Castle (Nathan Fillion) had to track down a real life vigilante, based on his vast knowledge of classic Marvel comic book heroes' motives, codes and canon. Basically, Castle was profiling a superhero — let the geek-out begin!

After mystery novel writer Richard Castle and Detective Kate Beckett were called in to examine a homicide victim who had been split in half with a samurai sword, it slowly became evident that they were on the hunt for a masked vigilante named Lone Vengeance, who also happens to have his very own web comic.

Clearly sponsored by Marvel, who is putting out the Castle comic book in real life, titled "Deadly Storm" (which also made a cameo in the episode) the episode's best part was when Castle puts up a superhero board in the precinct, mapping out the existing superhero costumes the murderer stole for his own look. Which we've included in the above clip.

But the awesome doesn't stop there — Castle profiles the mild mannered superhero, slowly uncovering the face behind the mask. Using his superhero MO expertise, Castle flushes out the truth in the interrogation room. When one suspect doesn't seem particularly upset about violating the code of the superhero, he knows instantly that this cannot be our murderer. And never loses his love for the subject even when facing down the murderer in a dark alley, Castle can't help but scream out "How cool was that!" All in all, a really fun look into the mind of a real-life superhero — but we really hope it serves as a warning to keep folks like these off the streets.