Letter of Lies is the 11th overall episode of Tegami Bachi
Lag and Niche begin their first delivery. On their way, they meet a fellow Letter Bee Moc Sullivan, who feels Lag is not fit for the job and feels there's no need to concern himself with the content inside the letters, for all that the Bees do is deliver them.
Lag and Niche arrive at the sender's house, to which, they meet a writer named Vincent Alcott. He writes fictional events of his day-to-day life in his letter to his mother. Lag objects this kind of behavior but can't do anything about it.
Deciding to deliver the letter, Lag and Niche begin their search and encounter an older woman, who happens to be Vincent's mother - the receiver of the letter. She leads them to her home, to which, they encounter a gaichuu, which attempts to destroy the bridge they were trying to cross.
After Lag and Niche defeat it, Lag's shindan hits the letter, revealing Vincent's memories to the woman Louisa, who really is his mother. However, Louisa knows that her son writes these kind of letters to her, and hopes that he will one day make his dreams a reality and come back home with pride.
Soon, on their way back, Niche shows Lag a letter that was hidden inside one of Vincent's books that Steak had eaten, to which, he realized that this is the letter that contain Vincent's true feelings. Instead of intruding on their business further, Lag decides to return it to its owner, Vincent.