If you mean about this, try finding Jester at night, talking to him about the topics, doing the 2 quests from him, getting the scene that trigger with Scar at night, then the one in the bandit camp when choosing to sneak in at night, i think submitting to the 2 bandits guarding the place might eventually lead to Logan being found, he will have the 3 purple ? marks if you trigger the scene with him in the bandit camp, you can choose to offer yourself in his place after that to free him.