Prime Prime immortals are dying like flies: nasty, violent deaths. The Hierarchs suspect Entropy, as usual, especially with all the rumors of demons' involvement. To top it all off, one of the Hierarchs is missing - Mazikeen.
Your mission as novice Temporals, should you choose to accept it, is to find Mazikeen, uncover his kidnapper, and bring him or her to a court of Immortal Justice. This entails much more than a mere detective job - it also means taking part in the Immortal Olympics and going plane-hopping with the best (or worst?) of them.
Should you not accept this mission, the fate of all Prime Plane immortals rests on your heads. (Well, it rests there anyway, but this is meant to make you more than a little guilty about not accepting - after all. you're supposed to be duty-bound and all that kind of thing, and if you don't do this, then who will? Huh? Did you ever think about that, Bucko?)