Lineage II's fifth anniversary event was originally scheduled to end on May 5, but has been extended until tomorrow, May 12, since it "did not cooperate as it should have," according to a post on the official site.

The event requires you to collect the letters A, C, E, G, I, L, N, R, S, Y, 5, and II from monsters to spell out the words LINEAGE II, GRACIA and 5YEARS. The letters will continue to drop until tomorrow's maintenance begins, which is also when the event NPCs will be removed from the game. Be sure to hand in all your letters before the NPCs disappear.