Nether Gate is a highly secretive, covert group of assassins that worked under the Falenan royal family. Its members undertook many dangerous and illegal acts over the years, including espionage, sabotage and murder. Divided into five divisions (Assassination, Intelligence, Assassin Training, Drug Development and Subversive Activities), the group trained their operatives while they were young children and graduated the survivors at the age of ten. The training completely brainwashes their operatives, forever altering their behaviour and appearance. For example, the former Nether Gate assassin Sagiri was trained to smile all the time to make her appear unassuming to targets and so is unable to change her facial expression, even years later. In the past, Nether Gate attempted to infiltrate Harmonia's Howling Voice Guild to steal their gun technology, but were rebuffed. They carried out political assassinations, such as the murder of Nakula's father, a New Armes chieftain who was advocating strong anti-Falena measures at the time of his assassination in 441. Its Drug Development division created many rare and dangerous drugs including Dark Arcanum, Raging Nostrum as well as other drugs which could kill a target instantly.
During the Succession Conflict in 439, Nether Gate operatives were used by both sides of the conflict (headed by Princesses Shahrewar Falenas and Falzrahm Falenas) to assassinate each others allies. Hiram Barows, Rosalind Godwin, Kauss Barows and Mardas Godwin were all murdered by Nether Gate assassins during the conflict. When Shahrewar gave up the right to the throne to her younger sister Falzrahm, Falzrahm had her sister murdered as well to ensure her succession to the throne.
After Arshtat Falenas took the throne, the organisation was officially disbanded with prominent members either fleeing the nation (to Nagarea), starting new lives (like Oboro) or moving underground and finding work for the Godwin administration (like Dolph and Childerich). As such, the House of Godwin continued to support the organisation is secret, allowing Nether Gate to play a key role in aiding the Godwin coup of the royal family in 449 before the group was dismantled again after the events of the Falenan Civil War.