Upon arriving in the system you will be hailed by Odo, who explains that the system has been nearly overrun by the Hur'q and time is a factor as you need to aid the Dominion and ensure as many refugees leave the system as possible.
There are three lanes in the system. The team will need to split up and destroy any Hur'q around. You will need to help out Jem'hadar ships in the system. You can find these by the green smoke coming from them. Fly to them and send power. There are nine ships to help and there is a time limit. Once this is done, clear out any remaining Hur'q ships.
Odo will hail you again and explain that the defense satellites need repairing. There are four of them. Once repaired you can activate them to tractor Hur'q ships to make destroying them easier. You will be fighting off the Hur'q at the same time and you will be able to repair the satellites at the same time. To find where they all are, press M to pull up your map and head to each location that is marked. The optional here to is destroy all Hur'q forces before the next wave warps in.
Odo will hail you again and tell you that the rest of the refugees are ready to evacuate. Your team will need to split up again and there are three lanes to cover. Once this starts, Odo will say something like 'Hur'q ships spotted at escape route Gamme. Get over there!'. Destroy the Hur'q forces and keep an eye out for any groups coming in as the transports are going down the lanes trying to escape the system to safety. A Hur'q Dreadnought will appear on sensors part way through and destroying it is optional.
After so long, Odo will tell you that they are speeding up the evacuation and that all three lanes will be utilized now. Fly back and forth and destroy any Hur'q you can. This will continue until the objective becomes to destroy any remaining ships. Once done, the mission will be completed and Odo will tell you that's everyone and we did what we could.
You will get a choice of Gamma or Fleet Marks.