After discovering the Charon Relay, humans began a rapid expansion thanks to their new-found connection to the mass relay network. Hoping to expand their territory and driven by immense curiosity about the galaxy, they began activating every mass relay they could find.

However, in 2157, their actions caught the notice of the turians, who found human explorers reactivating an inactive mass relay known as Relay 314. This was forbidden under the Citadel regulations after the Rachni Wars, but instead of negotiating, the turians opened fire. One starship escaped to warn the Alliance; a retaliatory force destroyed the turian vessels, and the situation quickly escalated into war.

To anyone who knows anything about Mass Effect and it's history, you might recall that this incident as the First Contact War. You might also recall that the Council stepped in and negotiated a peace that ultimately brought the war to an end. But what if the Council had been unable to broker peace? What if the war had dragged on beyond the liberation of Shanxi? And what if humanity was loosing?

Let's say that roughly two years after the Contact War had begun, following a string of Pyrrhic victories, the Alliance Navy has been devastated and it's frontier colonies have all but been lost. A quick and decisive win is desperately needed in order to bring the Turian Hierarchy back to the negotiations table on human terms. And that's where we come in, as members of a special operations team sent to destroy a Turian supply base at the border of Alliance-held space. Once it's destroyed, it's assumed that the Turian supply lines will be cut, and that the loss of food, ammo and other supplies will cripple the Turian expeditionary fleets and give the Alliance, if nothing else, time to recoup it's losses.