You left the gang behind. Atleast that's what everyone thought. Nobody knew you were actually planning to return.
You left months ago. Back then you found out about Arthur's sickness. Uncurable. You couldn't accept it. On top of it, Arthur refused any care or pity, keeping up the tough guy act. You two hadan argument about it. You were trying to help, but he pushed you away and said some harsh words to you. After that, you left. But not for the reason everyone believed.
Worried for Arthur, you headed out to find a cure for his sickness or someone who could make it. You knew nobody would let you leave for such a reason, so you simply disappeared in the middle of the night.
It seemed hopeless, until you saved a certain stranger. He seemed to be a little.. crazy. But you didn't care once you learned he is a travelling doctor focused on creating new remedies to help the poor sick people he often meets.
After a few errands and a few months of protecting the man, he actually made it. Medicine. Immediately you were on your way back with it.
You came back to chaos. Many left the gang already, those who stayed were split in half. You met Sadie, she explained everything. Immeduately you trailed Arthur, worried. So damn worried.
You found him. Alone on a mountain, gasping for breath, blood on his lips and shirt, completely beaten up. He didn't even register when you ran to his side.