Your objective is to seize the throne after defeating Zola. The whole map is covered with ice and you can only bring six units. You’ll be forced to attack the ice to thaw a small area behind it. You may encounter enemies when breaking through the ice so be careful. Don’t pair up units for the meantime since you’ll need as many possible units who can take turns to break the ice and attack enemies. It’s worth clearing all the ice since you’ll encounter enemies that can drop weapons, consumables, and valuable items that can permanently increase stats.
From the starting position, keep thawing the ice to the north to find a group of four enemies who’ll drop an Energy Drop and Vulnerary upon defeat. A bit to the north of that group is another enemy that has a Talisman in his possession. To the left of that soldier lies another soldier that carries a Goddess Icon. To the NE corner behind the wall, another soldier can be found with a Dracoshield in his inventory.
If you start thawing to the west, you’ll find a soldier that has an Arms Scroll. To the middle south, there’s a knight that has a Speedwing. A bit to the left is a mercenary carrying a Spirit Dust. Move a bit to the left to find another mercenary with a Seraph Robe. Further SW of the map, a rider has a Secret Book in possession. A bit to the middle-north of the walled portion to the south, there’s a fighter with a Heart Seal.
When you’re done clearing the town of ice, head to Zola and take him out to get a Master Seal. Seize the spot to complete the objective and finish the chapter. After the battle, Takumi, along with his retainers, Hinata and Oboro, will join your party.