Keep saves before the auction and before the heist. Countess Mignole sells the Viper armor diagrams during the auction visit; the later vault has a separate Viper steel-sword diagram. Advancing the quest without checking these one-time opportunities can leave a collector needing an earlier save.
Finish the auction conversations
Speak to the guests with Vivaldi before the event advances. Mignole is the important armor-diagram merchant. Hilbert offers a Gwent opportunity; the art conversation provides information relevant to the painting. Decide which purchases and card opportunity you want before moving on.
Check your crafting list after buying diagrams rather than expecting a completed armor set in your inventory. For the distinction between the early swords and Hearts of Stone equipment, see Viper gear opportunities.
Complete the heist preparation
The quest branches into recruiting a burglar, recruiting a safecracker and the seasoning task. Follow each journal objective before returning for the planned heist. Your chosen safecracker affects the later vault allegiance, so keep the recruitment save if you want to compare team outcomes.
- Complete the auction and conversations you want.
- Finish the three preparation branches.
- Save before the heist starts.
- Follow the entry and vault sequence.
Inspect before leaving
In the vault, resolve the Borsodi conversation and inspect the available containers before departing. The sought house item and the equipment diagram are different loot checks. Do not leave immediately after finding only the main objective.
This page covers collection checkpoints and progression, not an exhaustive optimal-loot route or a current exploit. If a one-time purchase is already missed, compare your earlier auction save rather than relying on an unsupported console command to change quest history.
Sources and version limits
- GameBanshee: Open Sesame — Original-game walkthrough; checked October 4, 2026. Quest route, not a verified 5.x playtest.
Sources checked October 4, 2026. We have not personally tested these steps on your save or hardware. Historical mechanics and reported fixes retain the limits above.