The Corpse Doctor is the 14th overall episode of Tegami Bachi
Dr. Thunderland Jr., a biologist in the Third Bioscience Division, as well as the head doctor in the Bee Hive, has a morbid interest in collecting and dissecting animal corpses, earning him the nickname of "Corpse Doctor."
Exhausted from firing too many shindans, Lag returns to the post office and meets up with Connor and Zazie. Dr Thunderland recognizes Steak as a rare Kapellmeister, a creature that is able to form a symbiotic relationship with the Spirit Insects.
Soon, Dr. Thunderland kidnaps Steak for "dissection", while Lag and the others chase after him. After the doctor is cornered at the front door of his lab, Zazie attempts to attack him for having taken the stray cats he befriended for his experiments. Lag hits the cage holding Steak and all of them witness Thunderland's flashbacks.
He is shown as actually a kind doctor who comes up with cures from the corpses he collects. He had taken the stray cats in, as there was a disease spreading around the neighborhood. Aria takes Lag to the lobby where she plays her violin to all the gathered staff, healing their spirits with her Heart Restoration shindan. Thunderland comments to Lag that Gauche Suede was one person who understood him, and wishes Lag some luck in finding the missing man.