A Tau expeditionary force led by O Vior'la Iur'tae'mont (commander Burnout of Vior'la sept) from the recently colonized Mu'gulath Bay.Burnout has been given command of the troops from the recently formed Mu'gulath bay as none have yet achieved the rank of commander . As the majority have not yet achieved veteran status due to the young age of the sept all of the battlesuit pilots are instead drawn from Burnout's home world Vior'la, including his personal XV8 bodyguard and right hand man Vre M'yen J'karra (Unforeseen Mirror) given the name due to his unusual battle tactic of waiting in the shadows and using the commotion of enemy fire to mask his own return fire. Shas'nel Shi'us was the first to be offered the title of veteran from Mu'gulath bay but instead humbly declined the opportunity to become their first battlesuit pilot instead becoming a cadre fireblade, hoping to train his fire warrior squad to become the first veterans from the sept. The commander has led the expedition deep into the segmentum obscurus to Mordian in an attempt to create a beachhead further into imperial space, before reaching Mordian Burnout's force stumbled upon the Eldar world of Ventus Amica where the Eldar there pledged themselves to the empire after five thousand years of separation from civilized worlds, allowing for a devastating assault on Mordian. Upon reaching Mordian many of the guard joined the empire in hope of a better life. despite this the Tau were driven back by the space wolves and fled to the Elnaur Delta in the Helican Subsector with Ragnar Blackmane's force in pursuit.

The Eldar of Ventus Amica first arrived on the planet when their Craftworld collided with it's namesake planet in an attempt to avoid a warp storm, the event was catastrophic but due to the efforts of the farseers on board crucial parts of the craftworld were saved, buried underground by the impact. Fortunately the casualties were lower than expected as many of the inhabitants escaped in light void capable craft. Once the dust had settled the survivors landed on the planet to see what could be salvaged from the remains of the behemoth that was once their home, A day later the planet became surrounded by the warp storm the Eldar were trying to escape trapping them on the planet. Despite the impact the planet proved to be hospitable allowing the Eldar to colonize the world. An unusual side effect of the interment of the the Craftworld's infinity circuit during the collision has caused the larger rocks that were thrown up in the collision to be held in the air by psychic winds caused by the infinity circuit, these winds blow the rocks about casing them to slowly drift around the planet, the winds have also allowed the Eldar to set up many windmills in their villages to help produce food and power.
The warp storm surrounded Ventus Amica for five thousand years, cutting them off from contact with other Eldar. The Amican Eldar are frequently visited by the Harlequin Masque of the Watchful Slaughter a troupe dedicated to the slaying of daemons of Tzeench. However the webway route to the planet is only known by the Masque as they believe it is too dangerous for others to travel.
When the warp storm finally subsided the Tau led by Commander Burnout discovered Ventus Amica and made contact with the Eldar there, Believing themselves forgotten by their kind the Amican Eldar readily joined the empire with approval of the Masque of the Watchful Slaughter.

After his return from the campaign in the Sanctus Reach system Wolf Lord Ragnar Blackmane was summoned to Mordian's defense from a mass tau invasion, hoping to find glory Lord Dragongaze and his personal retinue joined Ragnar in their mission. For such an crucial mission Ragnar brought the finest of his company: runepriest Brynjar Thunderhowl, Braum Mountain-Mover's thunderwolf cavalry, Ironpriest Ingolf and his Stormfang, Storm Chaser and the grey hunter pack Jarnhammar (read the novels Blood of asaheim and stormcaller for more on them). Ragnar was also provided with Bjorn the Fell-Handed and Murderfang's services as the mission could not be allowed to fail. Ragnar was also joined by the eccentric Tech Priest Genetor Dialecta, Xenobiologis, Xenologis known as Atrax Starkos who hoped to learn about Tau Biology, Technology and Culture in his quest for knowledge. Because of this near heretical behavior (and his erratic wandering mind and unawareness) his Forgeworld of Synford II were more than pleased to be rid of him. Despite his complete lack of interest in fighting the tau Blackmane still allowed him to accompany them as The Young King did not want to offend the Forge World as they were a large provider of ammunition for the Space Wolves. Equipped with his Ferrus Gravitator, a device that allows Atrax to manipulate Metal to his will, Atrax brought with him a group of Kataphron Battle servitors to act as bodyguards should things turn hostile. Upon their Arrival on Mordian The Space Wolves quickly drove off the tau who then fled to Elnaur delta, Ragnar opting to pursue his prey and finish the kill.

When the Space Wolves arrived on Elnaur Delta the fighting grew evermore fierce as the Sky Warriors slowly cornered the fleeing Tau. Before any Decisive attacks could be made the whole planet shook, something terrible hidden beneath the planet's Icy surface had awoken. Metallic warriors began to pour out from beneath the ice, the Necrons had Awoken. Slowly the Necrons drove back both invaders crippling their numbers in the process. Realizing the threat that the Necrons posed to the whole segmentum, the Tau Allied with the Space Wolves in order to best contain the treat of the newly awakened Necrons. Peace Talks between the Imperium and the Tau Empire have since opened up, while the campaign against the Necrons rages on.