Once you find the word "Ignite" after Zane talks to you, you'll head up a hill with words that say "Clear" on large rocks. You will want to use these as fast as you can, as it clears away the rocks blocking the lighthouse's light. This light will rotate in circles and kill the enemies. Dodge or run around and let the light kill the enemies, making sure you only use flares if anything. It is a pretty good distance, but eventually you will find a Safe Haven which is the end point. If you accidently fire a shot, reload your checkpoint.