The origin of the Deathwatch is disputed in several places but in the rulebook a page talks about a few centuries ago Ordo Xenos calls together some Chapter Masters and asked them to be a part of the Deathwatch. Well, I am throwing that out…. kind of. I am pushing that back to the Horus Heresy era at about the same time the Grey Knights are formed. But I wanted to create a place where I can bounce ideas off other Warmasters (GM's) :)
The game will begin with the end of the Ullanor campaign. I am going to have the PC's away from their squads, alone when they come across each other and then run a few sessions pushing to an orc leader. So, split apart from their squads and legions (multiple legions were at Ullanor, I believe) the PC's will play a few sessions to get familiar with the game system. Victory at Ullanor will be the second or third game session.
At the end of the Ullanor campaign, the PC's having saved the world basically - they find out that the orcs had a weapon they were going to destroy Ullanor with and escape the planet. So, Malcador the Sigallite talks the characters directly and offers them a place of honor where they will both be part of their legion and serve the emperor in a greater capacity. Once they agree, they recieve medals from the emperor for saving Ullanor along with a new duty. They would go forth with Horus to be forever on watch for the Xenos threats he might encounter. They are given black armor that the deathwatch would later use and assigned to serve aboard the Vengeful Spirit (Horus' Flagship).
A year later the characters will be involved with the Batttle of the Whisperheads and the Luna Wolves 10th Company. I am going to introduce the creepiness of the forces of chaos at this point with the SAMUS voice of the vox. While Loken is dealing with the actual SAMUS, the PC's find a few priests with warp powers that worship the voices - one of the first chaos cults led by a powerful psycher. Players also discover evidence of a secret warrior lodge.
Who is behind the secretive warrior-lodge? After a few combat driven sessions I wanted to start a more investigative and suspicion driven game where the PC's begin to unravel who is really behind the forces of chaos (Word Bearers and Erebus)
Planet Murder. Several legions are involved in the short campaign at Murder but it leads to events with the Interex. The players discover a transmission coming from Blood Angel's Captain Khitas Frome… the original captain of the 140th that requested reinforcements. The PC's are sent on a mission to recover the captain if they are able. This will be a short adventure leading to their first "boss style fight" with a hive queen of the megarachnids.
Interex Humans. This is the end of what I have actually planned. I try not to plan too far ahead because players have a tendency to throw everything off course. The PC's are ordered by Abaddon to investigate the Kinebrach aliens that are part of the Interex race. This would be the longest adventure in the bunch because they will see an Astartes (Erebus) flee from the Hall of Weapons. They do not recognize Erebus but they do know he is an Astartes. As they give chase, the characters must fight a Chaos dedicated Psycher and cult (very similar to the one fought at the Whisperheads)… connecting the two.
The next adventures will focus on Davin and the fall of Horus. While Tembra is hunted the PC's discover a new form of Xenos and must investigate - while they believe it is xenos it is actually Nurgle daemons and a cult. Once inside they find the sleeping quarters with items that would only be in the hands of a Astartes and they learn of a trap laid for Horus using Temba as bait… no matter what happens of course they will be too late.