Witcher 3 Dowry Quest Guide
Start Location: At the easternmost of the three hidden treasure icons on the map on the islands to the west of Oxenfurt right on the coast.
When you arrive at the marker, use Witcher Sense to find the dead body by the water that is indicated by the red glow. Loot the fellow’s body here for an Unsent Letter and a Slightly Bent Key – looting these will activate the side-quest ‘Dowry’.
Read the Unsent Letter in the Key Items section of the inventory. This will update the objectives.
It’s a good idea to meditate and prepare a this point as you’ll have a fight with a powerful monster in a moment. When you are ready to continue, use Witcher Sense to locate the chest by the grounded boat nearby. Use the Slightly Bent Key on the chest here to complete the side-quest.
This will also have the unintended consequence of triggering a fight. At this point you’ll encounter a level 32 Basilisk. Use your usual flying monster tactics on it (use AARD/Crossbow to bring it down) and avoid its spit and melee attacks as they’ll poison you. Once you have defeated the Basilisk, you’re free to go on your merry way with another completed quest under your belt.
Go you good thing!