Spoilers aren't cool here.
(Try The Howling, instead.)

We've long noted at T:FALSE BLUE that it's possible to get false blue links when making interwiki links. That is, you can link to totally non-existent articles at another Wikia wiki and get an apparent blue link.

• memoryalpha:Spock is half-Gallifreyan . . . on his mother's side
• wikipedia:This place isn't as fun as tardis.wikia.com
• w:c:jamesbond:"No, Mr. Bond, I expect you to regenerate"

As was confirmed today, however, this behaviour is not a bug in Wikia's deployment of the MediaWiki software. This is the way MediaWiki software works "off the shelf". In other words, it's supposed to do this, and it's nothing to do with Wikia.

That's why it's very important that you go back and check every inter-wiki link you make. Don't assume that because you got a blue link to Wikipedia that you've actually made a successful link to an article there.

czechout ☎ ✍ 00:40: Wed 26 Oct 2011 

Thanks to DaNASCAT for his help confirming this behaviour.