Don't visit the Durmstrang ship.

You realise that you can't go to the Durmstrang ship. Someone wants to harm you – you saw that when they put your name in the Goblet of Fire. And the nearest **** Eater, except for Snape, of course, is Igor Karkaroff, Headmaster of the Durmstrang Institute. You can just imagine Sirius' anger if you handed yourself over meekly to a **** Eater.

"Sorry, I can't", you say to Krum. "I'm going down to the Quidditch pitch soon for some practice."

Krum looks crestfallen, but doesn't argue with you. He leaves the library, and you return to your desk to do more work before going to the Quidditch pitch.