The Traders will feel an urgency to complete their business transactions in the sector as quickly as possible in order to retreat sooner to safer regions. In order to do this, they will elect to split up and carry out their various meetings and transactions separately. Then, once they have regrouped in six days, they expect that they will make haste to flee to a distant system. Again, their plans are inconsequential, as they will not unfold as planned.
The human traders will travel each to a different planet to conclude their business, and each will be in safety. They will not require your presence among them and are no cause for concern. The Tau Emissary named Kale'os Un'varas, however, will seek to complete an exchange on Hephaestus IX. You must accompany him on this voyage, for he will be in great danger once he arrives there, and death will attempt to lay its hand on his heart many times before one hour on the planet's surface has passed. It is imperative that it not claim him, and the duty to protect him will fall upon you. Though the loss of a single mortal life may seem serious among the young races of the galaxy, you must understand a greater purpose: If this Tau does not survive Hephaestus IX, many galaxies will fall under the heel of great evil and the light of a dozen Craftworlds will be extinguished. Though his purpose is hard to discern at this time, we have forseen that soon the fate of this one soul will determine the destiny of a thousand worlds.
For a thousand years, Hephaestus IX has been an unimportant world in itself, mostly populated with stupid Orks and almost-as-stupid traitor Imperials who seek to avoid the eye of their Emperor, but the face of that planet has changed considerably in the past several weeks. The Hive Fleet Daerkatta has been noticed by the humans as hastening a trajectory towards Terra Prime. Predictably, they have pursued a poorly-considered recourse to divert the Tyranids; a beacon has been planted on Hephaestus IX by Imperial scientists which has drawn the Hive Fleet from its course and lured them to deploy their savage Genestealers to its surface. For weeks, the cruel and vicious creatures have clashed with Orks and humans alike, and have become both more fearsome and intelligent. Now, even in this short time since planetfall, the Tyranids control Hephaestus IX, and the few remaining humans and Orks struggle for their existence.
Phase two of the Human plan to draw Daerkatta away from Terra Prime has begun; a sub-sonic agitator has been activated on the planet's surface which will cause the Genestealers to call to the rest of the Hive Fleet and beckon them to invade. Even to those who cannot scry the future, the short-sightedness of this plan is plainly evident, but the Farseers among us have seen that if Hephaestus IX falls to the Hive Fleet Daerkatta, so will numerous other worlds... including Terra Prime itself. It is for this reason that you are charged not only with the protection of the Tau Emissary, but also with the duty of neutralizing the Agitator, so that the Genstealers on Hephaestus IX do not call the forces of Daerkatta to the planet surface.
Weighty as your tasks may be, weightier still is this one last duty: Hephaestus IX is the home to a poor, angry fugitive by the name of Xavier, but you will know him as the Vessel. When you first arrive on the planet's surface, you will instinctively move alone an in the character of the assassin, but you must pause to notice the Vessel immediately, for he will be close. Not only must he live, but you must bring him with you from Hephaestus IX when you depart. If the Vessel is left behind then all else will be in vain. Again, the tasks which fall upon your shoulders while you tread upon Hephaestus IX are many, and fate has chosen a path for you which you would not have chosen for yourself. It is not for us to decide, however, and the exigencies of the time in which we live call us to great sacrifice for the sake of the future. As an Eldar warrior and prodigy, you above all should understand that the future is our charge, for our past has left us broken.
When your feet touch the ground of Hephaestus IX, the Vessel will pay you no heed; he will see you as another unimportant survivor of the Daerkatta Genestealer invasion and seek shelter from the fierce devourers. It will not be until the last moments on Hephaestus IX when you will find him again, but find him you will. At that time, you will know what to do.
Begin your short time in the ruined capital city by searching for the Agitator. At first it will seem impossible to find but, before long, your duty to preserve the life of Kale'os Un'varas will place it in your path. Beware, however; a fierce human warrior tarries near the device and will not suffer intruders. Do not engage him, but be certain that the device has been neutralized, even if not by your own hand.
The talons of Daerkatta scuttle around you and you will witness many deaths, even at a close distance. These should not concern you directly, but continue on your appointed tasks before you are overwhelmed.
When your missions have been carried out and you prepare to flee, you will be kept on Hephaestus IX by an urgent crisis that will arise in the short span of a single heartbeat; the Human Marine will seek to kill Kale'os Un'varas and will come very close to doing so. Only through powers which are Eldar in nature alone will you stave back the aggressor and bring both the Tau and the Vessel to safety.
Be vigilent and swift. Do not be distracted, but take advantage of the distractions of others. Move with a singularly determined speed and cunning and be the boldest among many. You have no time to reflect or pause; the talons of Daerkatta are outstretched not only for the throats of Humans and Orks, but for yours as well.
As Kale'os Un'varas, only having barely escaped death from a bolter shell (which, if not for his helmet, would have decapitated him) ran stunned and weakened to the loading ramp of the shuttle, Xavier the mutant priest followed shortly behind. Though dizzy and aching from a terrible gash in his chest from a furious Genestealer who got a little too close, he managed to reach the loading ramp and find shelter inside of the ship. It was the Eldar who came last, his face turned to the ruined city of Hephaestus IX, making triply sure that his charges had found complete safety before following them. In the passing of a few quickened heartbeats, his eyes met with the enraged visage of the Human Space Marine who sought to kill them for tampering with the Imperial Sub-sonic Agitator. The Marine rushed madly to them, Bolter blazing, seeking violent revenge for being slowed by the Eldar's Haywire Grenade, but he was stopped; the Eldar voice was inside of his mind and spoke to him in the weird voice which mingled with his own sub-consciousness.
"You do not see us, Human..."
"We are to your left... search there..."
"We are behind you... turn quickly..."
"Do you believe your eyes, Human? Check again? Check a second time..."
By the time the hissing, twisting voice of the Eldar psyche had cleared the Marine's head, the shuttle had lifted and was far, far from the ravaged husk that was once Hephaestus IX.