Moya contacted Cole and told him that an EMT was requiring his help. Meeting the wounded EMT, Cole learned that the Reapers have taken over his clinic and were attacking any pedestrians that walked past. The EMT asked Cole to defeat the Reapers so the clinic would be safe to run. Turning the corner, Cole witnessed a Reaper shoot a civilian at point range before spotting him. Racing to meet the oncoming Reapers, Cole quickly defeated them all before clearing out the remaining troops at the clinic, leaving the area free of Reapers and the EMT free to run his clinic. Moya called Cole once more, saying that there are more people out there that need help.
Note that this mission is technically treated as a side mission, as the main mission simply involves Moya informing Cole of the EMT, who will have a side mission indicator above him.
The objective here is rather simple, as it only involves clearing out a group of Reapers to save a medical clinic. After doing so, you will unlock the first of many medical clinic. This means that you will respawn at this location whenever you die. Unlike other story missions, completing this one will free an area from faction control.