Chapter 4 is where Resident Evil 4 Remake briefly stops being about survival and starts testing how well you can read cave walls. After the Del Lago fight, Leon needs two stone heads from shrines around the lake, but both are locked behind doors with symbol buttons.
The trick is simple once you know what the game wants. Each shrine has yellow markings nearby, and those markings match three buttons on the door puzzle. Press the right three symbols, ignore the rest, and the door will open.
Head to the Mural Cave after getting the boat. The locked shrine inside shows that Leon needs two key items before he can reach the Church Key Insignia:
Apostate’s Head
Blasphemer’s Head
Both are found at separate cave shrines around the lake. You can visit them in either order, but the Large Cave Shrine is easier to solve first.
The Large Cave Shrine holds the Apostate’s Head. When you reach the locked door, interact with the stone button panel and press these three symbols:
Dual Shell
Jellyfish
Circle-Cross
The clues are painted around the cave in yellow, but you do not need to line them up if you just want the answer. After pressing the three correct symbols, the door opens and you can collect the Apostate’s Head.
Watch for enemies in this area before focusing on the puzzle. It is much easier to clear the cave first than to rush the panel while Ganados are closing in.
The Small Cave Shrine holds the Blasphemer’s Head. This one is a little more annoying because some clues are split across the cave and only make sense from
the right angle.
Press these three symbols on the panel:
Three Snakes
Smiling Jellyfish
Biohazard
Once the door opens, take the Blasphemer’s Head from inside the shrine.
Before leaving, grab Hexagon Piece C from the same area. It is easy to miss, and you will need it if you want to finish the separate Hexagon Puzzle for the Depraved Idol treasure.
After you have both heads, return to the Mural Cave by boat. Place the Apostate’s Head and Blasphemer’s Head on the two stone hands beside the locked shrine.
This unlocks the Church Key Insignia, which lets Leon return to the church and continue the main story. Before heading back, it is worth checking the lake for extra treasures, Wayshrines, and the Red9 handgun if you have not picked it up yet.
