Oh, look! Here comes pointless conflict!
Not the good conflict that grows naturally from characters and the story so far, mind you. No, the kind that happens when the author feels that things aren't "exciting" enough, so they throw in an antagonist from nowhere with no advance warning.
Here's a tip for all you would-be authors out there. If you want to drop a plot-shaking new element into the story, give it a little foreshadowing. That way when it arrives, the reader will think "Oh, no! I should have seen this coming! What will our hero do now!" instead of "Oh, no! The author just airdropped some crap into the middle of the narrative! What should I go read instead?"