We're not here to tell home invaders how to invade, but here's a good rule of thumb: Do not attempt to burgle anyone who's studied medieval combat fighting. Otherwise you might run into Karen L. Dolley, a 43-year-old Indianapolis business-systems consultant who found an intruder in her house and did what apparently came instinctively: punched him ten times, boxed him into a corner, and held him at swordpoint until the cops showed up. The word "swordpoint" does not come up a lot in Indiana, yet here we are.

Not that there are good houses for home invasions, but this guy picked really badly. Dolley first developed her Wu-Tang style as an 18-year-old in the Society for Creative Anachronism, a group that re-creates pre-seventeenth-century European skills. Later, she was president of the Purdue Medieval Society, learning not only fighting tactics but arts, dress, dance, and how to make chain mail. These days Dolley does most of her scrapping with the Naptown Roller Girls, the local derby squad.

We caught up with Indiana's current leading viral star/ninja at a north-side coffee shop, where we were regularly interrupted by locals stopping to congratulate her. She's been on TV a lot. Also, she put a sword on our table.

How big of a sword are we talking here?It's actually in the car! I didn't want to just carry it in.

(Dolley retrieves the sword from her car.)

Here, feel it. I've cut myself on this.

(It's sharp. Also, the business guys on the other side of the window are definitely staring at us now.)

OK, first off: This is called a ninjato. It's a version of a wakizashi, a short Japanese sword. It's a Hollywood invention; they made it up for ninja movies. It's about as period as my phone. But it's 440C stainless steel, and a sharpened weapon.

So you hear a guy in your house…I wake up and this guy is saying, "Call the police," six feet outside my bedroom door.

Wait, "Call the police?"Well, he was tripping or something, but of course I didn't know it. I'm pretty hardwired for coming out of sleep. I was in a domestic-violence situation, and I have some PTSD from that. I've had nightmares where I wake up and think someone's standing over me, and I execute these perfect snap-kicks to what would be the intruder's solar plexus.

So you reacted pretty fast.It was this fluid movement—I came tearing out of bed, flipped on the lights, saw this guy who looked like Jesse Pinkman, and just started punching him in the face and saying, "Get out!" I hit him 8 or 10 times. But this is when the brain starts kicking in, and I'm thinking, "Why is he saying call the police? Is he trying to lure me into something?"

Is he putting up a defense at this point?He blocked like a little bitch [laughs]. I say things like that, and then I'm like, "Aw, this dude's gonna hear that," and then I feel bad. But if you break into my house, not only will I hit you, I will shame you internationally.

So, anyway, so I'm pummeling the guy, backing him into the bedroom. He gets into the corner, and I told him to get the hell down. He's freaking out, this crazy derby girl's pounding him, it's straight out of a sitcom.

Did you back him there on purpose?No, but that's where I keep my firearm. I reached across the bed, but I chose the wrong drawer. And my first thought was, "Did someone break in and steal my gun? I'm the worst gun owner! I'm not responsible!" At this point he's going, "Call 911, call 911," and I'm like, “That's in the cards, bro!” I go to the front room to grab the phone and call 911, and I come back and see that he's crawled around to the other side of the bed. He's crouched over, going, "Shh shh, turn the light off." And that's why I stopped hitting him. I didn't think this guy had a gun. I was concerned someone somewhere had a gun. But you still need to be aware of the fact that someone like that could change. That's when I grabbed the sword.

Right—so where does one keep a sword?Usually it's up against the wall, but he knocked it over, so I reached over him. I could have put a knee into his neck, but he was delirious. I had 911 on the phone at this point, and I said, “I'm Karen, here's my address, blah blah blah, and believe it or not I have him at swordpoint.” But after I had 911 on, he started reaching for his pocket.

That's bad.That's when I said, “Take your hand out of your pocket and put it in front of you or I will run you through!” Like, “You lie on the floor and think about what you've done, young man!” That's pretty much the voice I was using [laughs]. I'm really glad he complied. I would have done it. I leaned into him, put about five pounds of pressure into his kidney.

(I feel five pounds of sword pressure on my hand. For the record, five pounds of pressure from a sword is equivalent to roughly 3,000 pounds of pressure anywhere else.)

When the cops arrived, were they like, "Well, this is awesome!"IMPD were there in two or three minutes. And they told me how I was fully in my right to have done whatever I wanted. G.K. Chesterton said, “To have a right to do a thing is not at all the same as to be right in doing it.” I could have skewered him at any time. It was close, when he was reaching in his pocket.

It doesn't sound like there were any points where you were particularly afraid?Everybody's like, "You're such a badass!" No, I had fear. The lizard brain's always telling me I'm gonna get hurt, I'm not good enough, I should just stay in my place, that I'm saying something stupid—well, that's usually right [laughs]. We let fear control us. It's something you just have to work on. But it all comes down to: I'm not gonna be held hostage to fear.