A New Sea Route
Well, well, that wasn't completely unexpected was it? To chase after the Skyhold, you'll be heading for the war-torn continent of Eisenberg to the east of the Harena continent. Rest your tired heroes at the inn, then depart from Ancheim.
Next, head back to Al-Khampis and leave via its south exit. Back on the world map, approach the shore where you first landed to trigger a cutscene. In the middle of the night, Yew will receive a tip about how to reach Eisenberg via the shallow waters.
The following day, head back into Al-Khampis and speak to the pig by the entrance to "telepork" to Gathelatio. You could row back to Gathelatio if you want, but you'll save a fair amount of time this way. Back at Gathelatio, disembark from its southern shore and head due east along the shallow water.
Once you reach the south-most point of Eternia, a cutscene will play--as the mysterious voice foretold, the Eternal Vortex that previously blocked passage has disappeared. With nothing stopping you, continue following the shallow seas towards Eternia's south-east.
Eventually, you'll find a shallow path weaving through the rocky isles between Eternia and Eisenberg. At the end of the path, you'll be sailing adjacent to Eisenberg. Continue following the shallows south until you reach a lagoon on your left. Here, enter the small port to the north.
Yoko of Yunohana
You'll arrive at the picturesque House by the Sea, just like in Bravely Default. Except this time, somebody different awaits our heroes. Run up ahead and inspect the mess in the top-right corner for some Dried Remora . Then check the condition of the orange-clothed person nearby.
The aloof traveler introduces herself as Yoko, Princess of Yunohana. Apparently, she's been looking for her brother who left Yunohana and never came back. Yew, being the kind soul he is, decides to take her along while they search for the Skyhold.
With your new companion in tow, exit the dilapidated house via the door on the right.
A New Battleground
Enemy Tips : The imperials have come to Eisenberg! The Shield Van uses Iron Wall to take hits for its allies, while the Blade Van prefers to use Outflank to damage one and the Staff Van casts Thundara to zap your party. Focus on the Shield Van first, before taking on the rest.
Their robots are here too. The Iron Man (III) B-Type uses For Eisenberg to improve its allies' physical defence. Like in the Grand Mill Works, fry them with Lightning and punch through with the Mythril Knuckles.
Back outside on the world map, travel in a general south-westerly direction, along the coastline. When the coastline ends, keep going in the same direction, following the mountains below. Towards the south end of the continent, search around the end of the forests for a Roc Fillet .
Afterwards, head directly north from the southern forests, towards the barren wasteland that makes up most of Eisenberg. Soon, a battleground will appear to the north and a closed gate to its east. Head for the south-west side of the battleground to enter Eisen Bridge.
Enemy Tips : Valtoras use Chomp to try and bring a character to 1 HP; burn them with fire. Flare Lanterns use Book Burning to damage your party and inflict Silence. Give your magic wielders a White Cape and let loose with water magic. Or throttle them with a knuckle user.
At night, you'll encounter Ghosts--these spooky spectres use Fear to inflict Dread on one and Curse to drop a character's physical attack and defence. Set them alight with fire magic or quickly cut through with physical attacks, before Curse comes into play.
Searching for Clues
At Eisen Bridge, Commander Goodman is taking charge again. Not long after the Eisenberg civil war ended, the Glanz Empire has come to laid siege upon the lands. Currently, he's having a hard time keeping a single sniper at bay. Less embarrassing than a diva, we suppose...
Unfortunately, Goodman gets himself wounded so our heroes desperately need to return to Hartschild to seek help. Before leaving Eisen Bridge, inspect the bottom-right corner for a spare Mythril Spear. If you need to rest, don't be shy and let the Adventurer know.
Back outside on the world map, head due west, then follow the path in a north-westerly direction when you reach the shore. The city of Hartschild can be found at the end of the path, where the magma flow from the volcano reaches the sea.