Hey guys, I've got a session starting in about 4 hours, and I've totally overlooked the fact that I am going to have my PCs fight some Plaguebearers, but I do not actually know what I required to summon one. Any info you guys could give me ASAP would be greatly appreciated.

Right now I have got 1 servant of Nurgle, and 3 victims. As it stands right now, I am just assuming any necessary sacrifices have been made. I will probably have a couple of dead 'joy-girls' and some gutter-scum in a corner. The acolytes will arrive just in time to witness the bad guy jamming his fist full of maggots deep into the final victims guts. Then engage the acolytes, holding them off just long enough for the transformation to take place.

If it's not too late to pitch in, I see several avenues for summoning a Plaguebearer:

• Cultists have come into possession of a Daemon Weapon and wish to unleash the beast inside (Black Crusade - Tome of Blood 41).
• A daemonhost/daemon vessel has met its natural end, spawning the daemon (Radical's Handbook).
• Some psyker has invoked Perils of the Warp, destroying itself and leaving a daemon in its place. (multiple books, excluding Dark Heresy 1 - Core).
• Nurgle's Rot ends with the infected's rebirth as a Plaguebearer.
• The Shattered Hope scenario concludes with the appearance of a weakened Plaguebearer.

As an aside, I would not think that you have to have the summoning happen right in front of your player characters. Imagine them bumping a Plaguebearer as they turn a corner. Doing it this way gives an element of real-world surprise and provides an investigation opportunity after the battle. However, the daemon encounter may not be as memorable if they do not witness the moment it comes into the world. If this kind of situation ever comes up again, you could always use the opposite method to see how your players react. Best of luck in your session.

Personally, I would elect to use the first option. Leaving behind a Rune Weapon (an ex-Daemon Weapon) has some interesting roleplaying opportunities for any character with the slightest interest in taking it for personal use. Also good for reinforcing a character's faith in the Emperor should they be repulsed by the idea.