Journal & Quests (manual)
From Twilight Heroes Wiki
Journals & Quests
Each hero has a journal. It serves as a log of what you've done and a reminder of what goals you currently have. Mostly it tracks major plot lines: quests and missions to complete. When you're in a quest it reminds you of what you've learned and what you've accomplished, and lets you know what you still need to do. Once you've finished a quest it's documented in the Completed Quests portion of the journal.
If you're not sure what to do next, check your journal. There may be some hints or reminders there for things you could be looking into, or ways to finish quests that you've started.