A short guide to getting the semi secret weapon.
How to Find Out Where It Is
When you get to the lighthouse, go down to the basement and you’ll see a map.
Here’s the map, it contains a three number code.
Getting The Weapon
Go back to the start of the game, the moment where you first get outside. Hug the right wall until you see a cave over the water. Swim there, enter the three digit number from the map into the safe and the Undertaker is yours.
The Undertaker is a semi-secret weapon. It’s a pistol with an ammo capacity of 1, so you have to reload after every shot.
At the time of writing there are two different ammo types, incendiary bolts and slug bolts. Incendiary bolts set whatever you shoot on fire, and slug bolts do no damage but can shatter glass, light sources and activate buttons.
It has an attached flashlight instead of a crosshair. You can see which ammo type you have loaded, incendiary bolts are orange and slug bolts are black, you can see which one is loaded on the side of the pistol. (Pictured: incendiary bolt).