Watch A.D. Police File 3: The Man Who Bites His Tongue: Billy was an ordinary AD cop, but he was massively and mortally wounded in the line of duty. In an experimental project, he is made a total conversion cyborg, a cyborg with more than 90% of his body artificial. The only thing that reminds him of his humanity is his brain and his tongue, which he periodically bites to remind himself of his humanity. Unfortunately, apart from that, he suffers from total sensory deprivation which slowly begins to affect his mind. His efforts to feel something, anything, lead to tragedy.