Hey everyone, GM new to Dark Heresy, with an 8-man (literally ) group and looking to run a homebrew adventure. If advice could be given, it would be much appreciated.
Story as the PCs know it:
They've been picked up by the Inquisition for various reasons (individual to the characters, some know they are working as Throne Agents, some not) and left in clean, relatively comfortable but cramped individual habs on a space station for a few weeks, during which they haven't been allowed out but have been provided with exercise equipment and various useful data-slates. One day they're taken to a groundcar with blacked-out windows, and once they're let out, they find themselves in a a luxuriously appointed conference room with nobody else around. Here's their first chance to get to know each other and chat for a bit before a man identifying himself as "Interrogator Delta" enters the room and invites them to sit down. Cue him welcoming them to Throne service and detailing in brief what will be expected of them before assigning them their first mission, which he declares a milk run (experienced players at this point should begin groaning). Before they leave, he designates their team "Delta Dagger" and issues each of them a single-frequency comm-bead in dermal patch form, informing them that the only time they will ever hear their team name is from another Throne Agent, who will likely be senior to them, and that the only sources they will hear their name from are a face-to-face conversation and communications through the hidden comm-bead.
They will be deployed to the agri-world of Camilla in the guise of merchants there to set up advance deals for various exotic and quality fabrics that will be arriving behind them on a Charter ship, just in time for the festivities for Lord Arael's (planetary governer) announcement of his successor between his two sons Dominic and Albrecht. What they really are there for, of course, is to make sure things go smoothly and keep an eye on planetary unrest. Through some contrivance or other, they are invited to dinner with the Lord and his family, where they get to know the ruling family.
Lord Arael: personable, social, dedicated...in general, a good ruler. Under his hard-working rule, the planet has prospered. The only luxury he allows himself is hunting the planet's native and highly dangerous game, a pastime that he prides himself on. He has been found to be hunting more and more as the stress of having to choose between his sons begins to add up.
Lady Arael: slightly cool, but just as intelligent and dedicated as her husband. She acts as the voice of restraint to his over-enthusiasm at times, as well as providing more scholarly knowledge to compliment his social intuition and experience. Naturally, her preferred place to spend the day is the palace's well-appointed library, and she maintains many book exchanges to various places of learning on planet.
Prince Dominic: the elder brother, takes after his mother. Calm, collected, and bookish, he prefers intellectual exertion over physical. In light of this, his decision to fulfil his mandatory service to the planet in the PDF was received with curiosity. However, his intelligence served him well, qualifying him for promotion to officer ranks after completion of his service, and he is currently a captain of the infantry, leading a rifle company.
Prince Albrecht: the younger brother, takes after his father. Loud, boisterous, and confident, he enjoys good food, good drink, good company, and good music. His service placement of choice was as curious as his older brother's, as he requested a posting in Skywatch (think Coast Guard), a post known for its lack of excitement due to a dearth of space travel in the system and its distance from warzones.
Princess Iomedae: the youngest of the siblings, her age disqualifies her from selection as the next governor. She's quite shy around those she dubs as "scary people", but is very bubbly otherwise. Both her brothers dote on her, often taking her out at night past her curfew and bringing her treats.
Plot, GM version:
Basically, I want there to be hints that both parents are beginning to crack under the pressure to choose the heir, as many people they speak with will mention that the Lord and Lady have both seemed quite distracted and not particularly themselves. I'm thinking that they will be accosted by criminals looking to rob some rich-looking merchant types as they search for lodgings.. A nearby enforcer notices and comes to arrest the criminals, but is knocked out by a hidden one. Reinforcements arrive just in time for the PCs to polish off the last of the gangers and begin first aid on the enforcer. Suitably impressed, the precinct captain reports the incident upwards, where it goes high enough for the ruling family to notice and invite the Acolytes to dinner, then later to live in their household until their ship arrives. Here, one of the princes notes that most merchants aren't nearly as well armed or unconnected on-planet that they have no other place to live, leaving the implication to hang in the air. Shortly after, the PCs' groundcar is ambushed, with the attackers retreating after resistance and removing their dead and wounded.
This is meant to draw suspicion onto one of the brothers, who the PCs should think are trying to remove any possible interference from a coup attempt should he not be chosen. The Princes are in fact innocent, but neither of them are stupid and will recognize suspicion from the PCs for what it is, and react in an unfriendly manner. As the PC's suspicion rises in the process of their investigation (perhaps a few angry words between the suspected Prince and the Acolytes, or bureaucratic obstacles in the way of the Acolytes placed by the Prince in question), the Princess dies in a tragic accident at the palace. This should dispel any suspicion in the Princes and confuse the PCs. That night, the family eats dinner alone, while food is delivered to the PCs. They overhear a conversation between two servants about how the Lord and Lady were acting suspicious earlier in the day. With the ceremony in two days, the Acolytes must redouble their efforts at covert investigation, and the crisis hits fever pitch on the last day when both Princes are attacked by an unknown and placed in serious medical care.
Whichever one they suspect turns out to in fact be innocent (say, if they bust down the Lord's door with accusations flying, they instead find the Lady over his cooling corpse...). If the actual killer is the Lord, he has been corrupted by Slaanesh, using his pride in his hunting skills as a backdoor. Slaanesh began by whispering about his perfect shot into his ear through his rifle (now a Daemon weapon), and as his own mental fortitude cracked as the day of succession approached, its whispers turned towards his successful reign and how neither of his sons would be rulers as good as he. If the actual killer is the Lady, she has been corrupted by Tzeentch, who saw a ready convert in her belief in scholarly knowledge. She became even more reclusive, as well as becoming stingier with her books, a particularly strange occurrence as she had previously shared them willingly. The voices in her head began to talk about how she was the true power on the planet, the loud buffoon being merely the mouthpiece for her masterful plans, and about how she would lose much of that influence upon the succession of one of the brothers, who would no doubt seek their own advisers. Cue boss fight music here.
Any thoughts on the overall plotline of the campaign, places where things could go off the rails, cliches, good ideas, etc etc? Any advice is much appreciated.