It's the name, of course. Killer whale. Not "supportive" whale, or "empathetic" whale, or "I'm on my way to the canteen so can I get you a cup of coffee?" whale. No, it's killer whale. It's a whale and it kills.
Similarly, you know that when a minke whale gets in a killer whale's path in Frozen Planet that the minke will end up as whale-on-toast. It's the name again. Minke whale. There's something mimsy about minke. The beast might just as well be called "soppy" whale or "cotton-bud" whale. It is doomed.
Killer whales are my new pin-ups, the entrancing brutes that bring out the inner, whale-obsessed Captain Ahab I never knew was lying dormant. (Yes, I know Moby Dick was a sperm whale, but you can't have everything). Every time a killer whale rocks up on Frozen Planet I'm on my feet: "Thar she blows!" I tell you, if I had a mizzen mast in the living room, I'd climb it.
I started watching Frozen Planet only for the prospect of penguins and polar bears. And there have been some captivating scenes of romping, snuffly, snuggly polar bear cubs. And the penguins! Oh, who couldn't love a penguin?
Remember that great shot of hundreds of thousands of randy females barrelling down a snowy silent and deadly slope towards the males, all of them desperate for some penguin loving? Or the slo-mo film of roaring waves packed with surfing penguins? To borrow from Woody Allen, it looked like the most fun you can have without laughing.
But it is the killer whales who have captured my heart. They are terrible beauties; deepest black with those flashes of white, the males with their proud two-metre dorsal fins (men, eh?). Killer whales are wildly alluring to control freaks like me because they are so organised and intelligent.
They have their routines and they work to set patterns. I can't tell you how winning this is for someone who abhors chaos. Oh to be a killer whale, eating, swimming and playing as a family! It would be like The Waltons, but with plankton.
Even when they go in for the kill, the killer whales' calculation, cleverness and stamina are breathtaking. There was a haunting sequence in the first Frozen Planet when, in unison, they thumped their tails to make a wave that dislodged a hapless seal from an ice floe.
The whole thing was like a terrifying wet ballet choreographed by Matthew Bourne as the whales toyed with the seal that, exhausted, looked like it had reached safety. Only for a big, black head to pop out of the water and drag it, slowly, slowly, by the tail to its doom. The look of tired resignation in those big seal-eyes as they slipped from our view was transfixing and heartrending.
And of course the minke-hunt in episode three, a model of pursuit and capture over 20 miles (20 miles!). As killer whales became tired from the chase, others would smoothly move in to take their places, huge outriders on the ocean highway.
Yep, just call me Ishmael.
Frozen Planet continues tonight at 9pm on BBC1 and BBC1 HD.
This is an edited version of an article from the issue of Radio Times magazine that went on sale 22 November 2011.