Kyouka Jikken 3 ~Kurutta Bourei no Akume Idenshi Nyotai Kaizou Saishuu Shou~

He stood before the research facility, finally here. His mind trembled with uncertain dread. After decades, the mystery he'd been chasing was so close, but as he faced the concrete structure, a strange taste filled his mouth. In his hand, he held a letter detailing the secrets of this facility, where his father had once come. It was addressed to his mother, who died when he was born. The past, the letter, this eerie place... all would culminate in a maddening finale.