Wilderness Imagery Lighthouse is the 29th overall episode of Tegami Bachi
Lag is shown (hallucinating) working on repairs for the Wilderness Imagery Lighthouse (place) situated in the desert. An old man addresses him as "Lugh," his grandson, who was born and raised in the lighthouse. Lag tells his grandfather of hearing odd voices and his grandfather dismisses them as his own imaginations. He explains to Lag that he is all that he has left and not to think of leaving the lighthouse like his parents did.
While alone, Lag keeps seeing a strange four-eyed apparition telling him to leave and sees marks all over his body. Suddenly his grandfather appears and points a gun while muttering the word "hate". Lag realizes that the old man is not his grandfather and he is not his grandson. Soon, a flashback shows Zazie telling Lag about Jiggy Pepper who delivers express letters. Lag learns that Jiggy is heading to Liquid Sand River and goes to look for him there. Lag remembers who he is and realizes that the four-eyed apparition is actually Niche and Steak.
While they face the old man who blames them for taking away his grandson, Jiggy confronts Gaichuu Korona who has taken over the dilapidated lighthouse. After Jiggy destroys Korona, the old man disappears and Lag and the others escape from the crumbling lighthouse. Lag remembers going to look for Jiggy and finds Gaichuu Korona instead.
Upon entering the lighthouse to defeat it, he is overwhelmed and starts to hallucinate himself as the old man's grandson. Lag fires a shindan into the old man's journal to find out his heart. It turns out the old man was left all alone when his son refused to become the lighthouse keeper and left with his family. He began to weave fictional tales of his grandson still living with him and becoming successor to the lighthouse.
The old man eventually died and the lighthouse is left deserted. Jiggy explains that the journals the old man wrote were actually filled with hatred, and Korona consumed the heart within them, which overwhelmed Lag. However, thanks to Niche, who is immune to the hallucinations, Jiggy was able to easily defeat Korona. Jiggy warns Lag not to be taken in by emotions within letters, but to be strong. After paying his last respects to the old man, Lag and the others ride home with Jiggy. Jiggy tells Lag that he received a letter from Nelli, his sister, and thanks him for his help.