Nostalrius Begins - Quality wow vanilla realm (1.12)

Was in DM East tonight, and the little imp that you get the Crescent Key from, he just disappeared. The first two times talking to him worked fine, but when we got to his final spot where you fight him, he just wasn't there.

What happened?

Happened to me to. For some reason, we found him at his initial spot by the entrance. Do the dialogue one more time, and he runs straight to the final spot.