This guide will briefly explain where to find the Portal easter egg in the Witcher 3. This reference is found during one of the secondary quests in the Blood and Wine expansion.
The Witcher 3 is filled with its fair share of easter eggs for players to discover. Thus, it comes as no surprise that the Blood and Wine expansion also features several video game and pop culture references of its own. For this guide, we will help you find a subtle nod to Portal during one of the secondary quests in Toussaint.
As you can guess, this Portal easter egg will have something to do with actual portals in the Witcher 3. You’ll also find a somewhat different version of the infamous Portal cake and companion cube in the same location, in case you had any doubts as to the clarity of the reference.
To find this Portal easter egg, you must play through a secondary quest titled Turn and Face the Strange. This quest becomes available after completing a portion of the Blood and Wine main story quests. Play through a small bit of the main DLC questline, then explore Beauclair. A messenger boy will approach you with a letter. The Turn and Face the Strange quest will become available once Geralt finishes reading the letter.
Begin the quest and play through until you reach a part where you need to navigate through portals. When you find the room with two floors of portals, drop down to the lower floor. Pass the statue and climb up the rocks to reach the second level on the opposite side. Enter the middle portal. Walk past the next portal ahead on the left, and drop down a small opening in the railing to the right. There will be a portal directly behind you when you drop down. Go through this portal.
This portal takes you to a room with a box in the center. If you look closely, you can barely make out the faded hearts on the outside of the center box, which is a reference to Portal's companion cube.
On the right is a chest that contains a cake item. It just so happens that this particular cake bears a strong resemblence to the cake from portal. As you turn to leave, notice that the color of the portal is now orange instead of blue, much like the colors of those used in the Portal game.
Upon finishing the quest, the new Mutations system will also become available for you to use, provided you have enough skill points and money. For details on how this new system works, head over to our guide on How to Use Mutations in the Witcher 3.