Venturing to the bustling city of Bat Saha is one of the key elements of the Chapter Zero "starter quest" of Book of Travels. It lets you optionally learn to read the language, as well as gives you hints at your origins as a "Dandelion." To get to Bat Saha you must venture to the port town of Myr (which is in the central area of the western region of Braided Shore) and take the ship there.
The whole chronology of the starter quest is as follows:1. During most new-character spawn points, you'll be guided by nearby NPCs to a teahouse which you can get optionally healed at for the
Reached Safety achievement.
2. The workers there will guide you to
Bat Saha island to find the
Dandelions Temple. Both of these locations are achievements.
3. Speaking with the guardians at the Dandelion Temple will guide you to the Deeplander, usually found in their cave on the western side of Bat Saha.
4. The Deeplander guides you to the robed teacher in the upper/northern part of the city itself. You must "Rest" (sit) down before them to trigger their dialogue. Afterwards, they provide the skill card for Vellan. You must use the item in your Inventory, then go into your Skill Book and "Learn" (equip) it.
After this is complete, there is no direct story arc to follow. However, the
Singer and Kasa Incident questlines as well as their connected
Vastila and Nightbathers arcs contain most the lore revolving around Chapter Zero's reason for Kasa being closed.