The frost temple
Climb the temple and face the Hoarfrost Wyrm.
The frost temple stands in the cold region east of the high flats. It has five floors, three treasure pedestals and the Frost Engine at the top. The boss details are in the spoiler section below.
Before you go
The cold region's surface and shallow rock are at -10 °C, cold enough to damage you. Iron armour or better prevents that damage, as does the Wolf Pelt dropped by Frost Wolves. Cold resistance adds across all equipped armour and accessories.
Water freezes into Ice here. Keep any water you need somewhere warm. The ground is Snow. Digging snow gives you nothing. Heating it makes water, which freezes into ice in the cold. You cannot carry or make snow.
Watch for Frost Wolves on the surface. They keep their distance when you face them, then lunge when your back is turned. They growl before springing. You can only face one at a time. Ice Wraiths pass through walls and fire beams, while Snow Harpies rise above you and dive. In shallow caves, Rime Skitters spring toward the spot where you stand, so keep moving. Icebacks brace before rushing through the caves or across the surface at night. These creatures live only in the cold region.
Reaching the temple
Walk east until the snow starts, then continue to the temple. It stands on a level base with a doorway on each side.
Two broad frozen lakes lie on either side of the temple. You can cross or mine their ice. Beyond the lakes, sloping openings lead to ice grottoes with hanging ice, rimestone and exposed iron seams. You can gather materials there before entering the temple.
Climbing the floors
Each floor is narrower than the one below it. The first four have ledges that form a staircase to a hatch in the ceiling. Each ledge is one jump above the last. The staircases alternate sides, so cross the hall after each hatch to find the next one.
Ice Wraiths can follow you through the walls, and Snow Harpies can dive from above while you climb.
The three treasures
There is one pedestal each on the second, third and fourth floors. Each stands against the wall on the side where you enter through the hatch. Turn around as you arrive. Right-click a pedestal to take its reward.
- Second floor: Culverin Loader doubles some of your shots.
- Third floor: Slagmaw Gullet makes an unloaded tool's shots leave fire where they land.
- Fourth floor: Cinderling Ash leaves hot embers behind you as you run. Keep it away from anything flammable.
These charms also drop from Culverins, Slagmaws and Cinderlings underground, each at about one drop per fifty kills.
The Frost Engine
The top floor is an open chamber under the spire. The Frost Engine stands in the middle, with a pale moon disc above it and a beam of cold light rising to the ceiling. Walk close to the disc and a right mouse button icon appears.
Right-click the Frost Engine to summon the Hoarfrost Wyrm. You do not need an item, and nothing is consumed. Only one Wyrm can be awake at a time. While it is active, the beam goes out and the disc turns violet.
The Hoarfrost Wyrm: spoilers
The Hoarfrost Wyrm has a flying head and a long chain of segments, each with a crystal on its back. Its body follows the path of its head.
Hit the segments
While any segment has at least 80% of its health, the head takes only a quarter of your damage. Damage a segment below that point and its crystal goes dull, so it stops protecting the head even while it remains attached. The health bar shows a pip for each living segment and says ARMOURED while any still protect the head. Killing a segment closes the chain behind it. The body is a large target and passes near you often.
Attacks
The Wyrm never uses the same attack twice in a row.
- Frost breath: It hangs to one side, opens its jaw and marks a cone with dotted lines. Move out of the cone or behind the altar before it sprays frost.
- Dash: It rears back and a dotted line marks its path. Step off the line before it lunges.
- Icicles: It rises, and icicles form on the ceiling above you. Move away from the dotted lines beneath them before they fall.
- Shard ripple: The crystals on healthy segments flare in order. Each living segment fires shards from both sides, from head to tail. Stay out of the body's line.
- Coil: It circles you and fires bolts inward. Escape through a gap, or kill a segment to make one.
Second phase
When most of the body is gone, or the Wyrm's health gets low enough, its crystals and eyes turn violet. It moves faster and dashes twice, with the second dash coming straight back at you. It also gains a nova: it rises, a ring closes around it, and it fires two staggered rings of shards in every direction.
Beating it drops the Wyrmplate, which adds heavy armour, reduces contact damage and slowly restores health. The game records the win, and you can summon the Wyrm again. If everyone moves far away, the Wyrm and its body leave. Return to the Frost Engine to start the fight again.