Here is the guards logic - "Hmm, the boss is dead, lets not follow the non-suspicious bloody footprints leading away from the dead body into the closet, lets run around like idiots. And we'll stop the alarm after 15 seconds, because the killer has surely goten away after the long period of 15 seconds."
-.-, pointless in the end. Apparently you save the world by sacrificing yourself to restore a fountain, and "There will be tales of you, for all of enternity." I can imagine it now, "The Epic Tales of Someone turning a fountain back on," :P