Elwíng @ Die Nachtwache - Game Guide - World of Warcraft
Small story: He was stuck on ~ 35 Splinters of Atiesh after having cleared Naxxramas for the very last time before the Wrath pre-patch would hit the following week, and so thought his chances of finishing Atiesh were gone.
However, the Naxx pugs I lead with a couple of friends had just finished our last staff the week before, and so we had nobody to give splinters to for the final raid. Against the odds, we came into contact with him and he swiftly transfered over, resetting his raid lock, and finished his Atiesh. His last fragment dropped in our final wing before the Frostwyrm lair, so he hearthed out, grabbed the quest for the Staff Head/Base and came back in for the Kel'Thuzad kill.