The Battle for Horizon Base took place during the war between the First Order and the Resistance. It saw the operatives Poe Dameron, Finn, and Gannis Ducain undertake a journey to the outpost of Horizon Base in order to recruit the Oruan resistance group who had fled there after the First Order took their homeworld, Oru. Mezlo, the leader of the Oruans, was hesitant to join the Resistance, but eventually promised to provide assistance should they ever ask. After a few brief encounters with First Order stormtroopers on the station, the Resistance crew escaped in the Millennium Falcon.
At Horizon Base, Finn was hiding from stormtroopers as he contacted Poe Dameron that things were not going to plan. Poe told Finn that the mission was very important for the Resistance and the General Leia was counting on him. He then asked Finn if his partner could handle this. Gannis Ducain showed up behind Finn and told him that he learned his lesson after he stole the Millennium Falcon.
Finn and Gannis Ducain grasped by a Candori
As Finn and Ducain were talking a stormtrooper stopped them and asked to see some identification. But instead Finn shot down some barrels that were above the stormtroopers, knocking them down. Finn and Ducian then ran inside the base and Ducian told him about his past mistakes and how he didn't feel right for the mission. Finn reassured him that he was part of the Resistance now and that his past mistakes were behind him. But as he was talking he was interrupted by a Candori which picked up both Finn and Gannis.
Below them was the leader of the Oru resistance, Mezlo who used the Candori as protection against who he thought was First Order personnel. Finn and Gannis told Mezlo that they were with the Resistance and they were here to help them. Mezlo told the Candori to release them but refused to join the Resistance. He told him that he almost defeated the First Order off his planet even though the First Order had a force ten times the size of the resistance. He believed that the Resistance were not warriors and lacked the power needed to combat the First Order. Finn and Ducian told Mezlo about how they joined the Resistance. This caused Mezlo to reconsider for a minute, admiring their passion. But they were found by the stormtroopers who told them not to move. But another Candori came up from behind the stormtroopers and picked them up. Finn contacted Poe and asked him to meet them in Hangar Five with the Falcon for pick up as a firefight ensued. Finn once again asked Mezlo if he would join the Resistance but he still declined. As they escaped, Mezlo did promise to answer the Resistance call for help when it would be needed.
On the Millennium Falcon Finn reported to Poe that the Oru resistance would not be joining. Poe was worried as he mentioned they were still on their own. But Finn told him that while the First Order might have the manpower and the firepower, Ducain said they do not have the honor. He also said the Oruans will fight with them when the time is right and they would not be the only ones.