Trying to decide what story to go with. The original Flash game had a story that started like this, slightly altered:
It was only a short time ago that planets of the cluster were first visited by the Sav. Their ships were not large or powerful but they could travel between stars in mere hours. This gave the Sav their power. Though their weapons were little more powerful than the other planets the came quickly to dominate. They called their travel technology "warp" and they held it secret and held it close.
Then one day their advantage was lost. A Sav vessel was disabled and then "rescued". It was not long before warp technology was stripped and disseminated through-out the cluster. All was not lost for the Sav. By then their influence was vast through economic dominance nurtured through their past monopoly on warp. From a trading empire they shifted to military power. What they couldn't dominant by economy and warp they dominated by force of arms.
The planets under the Sav Influence and those outside lost their balance. Whereas before warp they had no contact with each other except through the Sav, now they discovered each other. Sometimes trading, sometimes fighting. Borders, influences, wars and unrest abound. The Sav treat them as misbehaving children but they are growing up fast and the Sav are losing control. Militaries, rebels, militias, privateers and pirates are all at work. A new equilibrium seeking itself is now disrupted: a ship has been found.
From somewhere, entering the cluster, floated an unknown vessel. Collected by subjects of the Sav it was held awaiting transfer until stolen by privateers. You are those privateers. And your new ship is powerful.
(I'm so sorry that so much of that was written in a passive voice)
OR
A simple story with none of the political stuff.
The decision will affect missions design.