Romancing SaGa 2

This achievement is earned relatively early in the game (second bloodline). If you want to be able to recruit the Vagabond you cannot fail to help Cat, or complete the Infiltrate the fortress without the help of the thieves guild.

Shortly after obtaining the first heir, Gerald, you will be given a quest to Infiltrate the Fortress, and begin to hear rumors of a thief in Avalon. Instead of going to the fortress, you must go back to Avalon and try sleep in your bed on the third floor of the castle. The game turns to night, and you are free to move about the castle. Leave the castle and go into the weapon shop in town (the one on the left). Go into the fireplace, which will bring you onto the rooftops and jump from roof to roof until you head into the castle window.

There will be a short cut scene with Cat, and she will leave, heading back out onto the rooftops. Follow her and you will notice she is surrounded by monsters. You MUST offer to help her. After this you can leave the rooftops and go to sleep in your bed.

When it's light out talk to the barkeep in Avalon and ask him about Cat. He will tell you to speak to the custodian in the Cemetary (follow the white picket fence along the top right of Avalon) and talk to the old man near the hole. This brings you to the theives guild.

They request you kill a monster for them in the sewers. Agree to help and head to the sewers through the bottom left door. Dispatch the obvious boss monster, and head back to report your progress. Then ask the theives guild to help you infiltrate the fortress. Cat will head to the fortress and you can meet her there, in one of the houses before the fortress. In addition to sneaking you into the fortress, she provides you with swords that point you toward treasures and the boss room.

Once you beat the fortress, you can return to the thieves guild and Vagabonds are now recruitable characters.