On Thin Ice best choices: Walkthrough & Combat Tips

On Thin Ice is a late-game main quest in The Witcher 3: Wild Hunt, and the best choices happen before the first conversation that launches the final battle. Geralt reaches the Nilfgaardian camp on the Marlin Coast while Avallac'h explains the plan to summon the Naglfar. Ciri is not allowed to join the initial battle, regardless of the dialogue choices selected during the briefing.

The most important decision is when to speak with Avallac'h beside the boat. Until that conversation, Geralt can still travel, upgrade equipment, collect ingredients, finish side content, and use the temporary camp services. Once the battle begins, the camp disappears and the quest moves through several major combat sequences without offering the same preparation window.

Video Highlights:

• The battle begins at the Nilfgaardian camp on the Marlin Coast.
• Ciri fights through Wild Hunt forces before confronting Caranthir.
• Geralt battles Caranthir, reaches the Naglfar, and faces Eredin.
• The quest leads directly into the next stage of the final storyline.

A quartermaster near the camp can provide repairs and blacksmith services before the battle begins. Some ingredients and weapons are also available inside buildings. However, taking items from containers in front of Nilfgaardian soldiers is treated as stealing and can cause the camp guards to attack. The safest approach is to use the services, inspect your own inventory, and avoid unnecessary looting.

One early quest detail deserves attention: the Contract: Devil by the Well quest may fail if it has not been completed before speaking with Avallac'h, depending on the ending path. Players pursuing a clean quest record should finish that contract before beginning the final sequence.

For a quest-by-quest reference, consult the On Thin Ice walkthrough on the Witcher Wiki, especially its sections on objectives, rewards, and known quest issues.

Once you are prepared, speak with Avallac'h to begin. The Sunstone is used to call the Naglfar to Undvik, but Caranthir freezes the forces gathered at the coast. Ciri then takes control of the situation and uses her Elder Blood abilities to push through the Wild Hunt.

The best choice during this portion is not to overthink enemy elimination. Wild Hunt enemies spawn continuously along much of Ciri's route, so advancing toward the objective is more important than clearing every opponent. Ciri's mobility and Blink ability let her break through groups quickly.

The Ciri segment is designed around forward movement. Her enemies can reappear, so stopping to defeat every group wastes time and increases exposure to unnecessary attacks. Blink is particularly useful when several enemies are close together, while her Elder Blood aura helps her cut through the advancing formations.

The first Caranthir sequence ends after he has lost roughly one-third of his health. Ciri breaks the orb on his staff, but the explosion incapacitates her. Geralt then resumes the battle. This transition is scripted, so do not treat the first phase as a standard boss fight that must be completed entirely with Ciri.

Caranthir uses ranged magic, teleportation, and Ice Elementals. He can launch projectiles from a distance and reposition frequently, making uncontrolled aggression risky. The safest approach is to maintain room for movement, watch the direction of his attacks, and use the arena to reduce pressure from summoned enemies.

Quen provides a useful safety layer when a projectile clips Geralt during repositioning. Yrden and Magic Trap can also help manage the space around the fight. Ice Elementals do not need to become the main target immediately; instead, position them between Geralt and Caranthir when possible. Caranthir's attacks can damage his own summons, giving Geralt an opportunity to survive while the battlefield clears.

At low health, the battle moves into a cutscene. Geralt pierces Caranthir, and the mage teleports them both underwater in a final attempt to kill him. This is not another extended combat phase. Swim toward the surface immediately. Killer Whale can provide additional breathing support if it is available, but direct movement is the main requirement.

After surfacing, Geralt can meditate before continuing toward the Naglfar. This is a useful recovery point because it gives you a chance to restore resources before the Eredin encounter. Use it instead of entering the next fight with damaged equipment or depleted healing supplies.

The route to Eredin contains additional enemies, but many of them can be bypassed by continuing toward the Naglfar. Geralt encounters Udalryk and Hjalmar during the approach, then reaches the ship as Eredin fights Crach an Craite. The confrontation with Crach is part of the quest sequence and leads directly into the final boss battle.

Eredin combines sword attacks, teleportation, and ranged magic. He is dangerous when Geralt attacks without a plan, but he can be staggered and punished during specific openings. The strongest general approach is to stay patient, avoid attacking into his guard, and use short windows after his ranged attacks or repositioning.

Rend can be effective when charged correctly, while Whirl can work when activated at a controlled moment. Repeatedly using Whirl without considering Eredin's parry can waste stamina and expose Geralt to a counterattack. Players without Rend should wait for Eredin to finish a ranged action, since he remains more vulnerable while stationary.

The fight changes location when Eredin throws Geralt through a portal. On the icy plateau, maintain the same principles: use measured attacks, avoid unnecessary trades, and watch his teleport timing. When he opens another portal back to the Naglfar, follow it promptly. Large magical projectiles begin falling from above, so lingering in the area creates additional risk without improving the outcome.

Near the end of the battle, a cinematic sequence resolves the fight. Eredin reveals that both he and Geralt were manipulated by Avallac'h, then dies after the final exchange. Yennefer arrives through a portal and pulls Geralt away as the remaining Wild Hunt forces close in.

Use this checklist before committing to the battle. The quest is structured as a final sequence, so careful preparation has more value than trying to correct mistakes after the briefing.

A few technical issues can affect the quest. Caranthir may occasionally stop progressing after the transition from Ciri to Geralt; reloading the previous checkpoint is the practical response. If Geralt is heavily over-leveled, particularly in New Game Plus, Eredin may appear to remain alive while the game waits for a scripted portal transition.

Other reported issues include a quartermaster icon remaining on the map after the camp disappears and unusual Wild Hunt spawns near the sea northeast of the camp. These problems do not represent intended choices, so reloading a recent save is preferable if the quest stops advancing.

The camp itself is temporary. Once the battle starts, its services and supplies are no longer available in the same form, and the location returns to a deserted state afterward. Treat the pre-battle area as a preparation hub, not as a permanent merchant location.