Both Annie (older, gray) and Zoe (younger, black) are in the basement by the sliding glass door. I head outside to empty the dehumidifier water, and, as usual, I let Annie slip out with me to enjoy a minute of eating grass. (Zoe is still too young to get to go outside.) After I'm done with the dehumidifier bucket, I haul Annie back inside. As soon as I put her down, she gags a little - which is pretty normal after she's been chewing on grass. But while she's doing this, Zoe goes into full alert: ears flat, back arched, tail fluffed. She's staring right at Annie, and she starts doing that scary alley cat yowl. And not the I'm-in-heat yowl... the feral, violent yowl.

I start telling Zoe "Knock it off, snap out of it" but Annie leaps for her and the two go at it. Suddenly it's a full fledged catfight, complete with that horrible human-sounding scream cats can pull off in times of duress. You can tell this is much more than the usual scrapping that goes on; this is serious. Although I can hear my Mom telling me "Don't bother trying to separate fighting cats" I dive in anyway. They break it up, but Annie chases Zoe upstairs.

By the time my bipedal frame can get me after them, they're circling like West Side Story. And Zoe has literally had the shit scared out of her: there's a couple little fresh cat turds dotting the kitchen floor. Both cats are growling and hissing.

I manage to scoop Annie up, although that doesn't stop the growling. I am now completely afraid, because I have no idea how this started or what to do about it. I carry Annie to the living room and return to see Zoe, but she's still deep into instinct... now hissing at me. Annie runs back in and spooks Zoe to dash into the laundry room, so I lock her in there.

I'm already late for work - and there's no way I can leave them like this. I quickly set up an emergency bivouac in the upstairs bedroom for Zoe: litter, food, water, toys. After a couple minutes, Zoe lets me ferry her upstairs. Shut inside the back bedroom, Zoe calms down and starts purring with me. But before I head out for work, I open the bedroom door - Annie is lurking on the other side - to see what happens. They lock eyes, Zoe falls back into alert, and they both do that dangerous low growl again. Door shut!

When you see your cute little pets act like this, it brutally reminds you what they're capable of. Your pets are not just mobile, toy-like, eat-and-shit machines. They are animals, built with innate abilities and cruel instincts that you or I can't imagine. "Domesticated" really just means "taught to eat processed factory leftovers from a bowl."

My guess is that Annie brought in some crazy scent from outside. Rabbit piss, feral cat piss, gorilla piss, I don't know. Whatever it was, it tossed Zoe into a full-body scare... which Annie interpreted as a dire threat. I have rarely been as frightened and upset as I was this morning, watching my girls try to kill each other. Threw my entire work day off. New rule: Annie no longer gets to sneak outside during the dehumidifier ritual, at least not until I can scour the area for dead moles or other clues.

I rush home as soon as I can. I open the deck door to hopefully let in more outdoor scents. I spring Zoe from her bedroom, and she seems normal, happily chirping as she trots down the steps. She walks right by Annie. No reaction from either feline. In fact, both are more interested in my smelly sandals. Status quo re-established. Hours later, they're both resting near me as I type this... Zoe doing some lick-bathing on the iMac desk, and Annie passed out on the PC desk.

So that was frickin' nuts.