Eisen ended up just going to bed on the couch and then spent a little bit of time speaking to the others about general new developments. It seemed like Brody just finished his level-up quest and was now getting started on his next task, which required him to learn a specific technique from a specific place on the island-group, so he was currently travelling back there for that very reason.
The old man was pretty curiou about what kinds of things these tasks could end up being. The 'technique' that Brody was supposed to learn was obviously something specially chosen for him to do, so the others woudn't get the same task.
Either way, there was not much reason to try and speculate about it without the possibility to find out. The second task from the notes could entail literally anything and everything that one could think of. Eisen would just need to hurry up and keep hunting monsters to find out.
