Nebula

Nebula is a very prominent corporation in Baccano! originally a mysterious organization, their name and brand have been mentioned many times throughout the story. However, the corporation itself ties closely to the immortal ensemble cast spanning centuries and even has ties to another series Durarara!!.

1931 - The Grand Punk Railroad
They built the transcontinental train the Flying Pussyfoot, on which the events of the 1931 Grand Punk Railroad arc. They also compensated and silenced many of the passengers by paying them off and with Senator Beriam's influence, hid the incident from the world and decomissioned the train after its maiden voyage.

1932 - Drugs and Dominos
They are mentioned through Bartollo Runoratta in tracking down Dallas Genoard to test incomplete immortality. They also are implied to have secured drugs that Begg was using for Roy Maddock.

1933 - The Slash
Mist Wall, a grand building owned by Nebula, is the sight for the climactic conflict in the two part storyline. Huey Laforet plots to bomb the location and kill its employees for an experiment, summoning Larvae and Lamia, two homunculi groups. In the struggle, the Camorra and Mafia groups consisting of Martillo families and Gandor families along with Chicago delinquents converge on the building through coincidence and misunderstandings. Senator Manfred Beriam oversees the experiment as he his the owner of the building, revealing he allowed all 1200 of its employees to become incomplete immortals and reveals that Nebula will go the distance in ending the Immortal threat and Huey's terrorist acts.

Once the dust settles, Mist Wall is left alone as all the factions of the storyline separate once the rain in New York subsides. Senator Beriam clears the incident once more.

1934 - Alice in Jails Street Episode
Due to the escalating problems of Lamia in Chicago, they hire help from the Russo family by giving them incomplete immortality. Placido hires Graham Specter to end the Homuncli or face dire consequences.

They later are mentioned when several buildings which are ambushed by the Lamia and Larvae factions in 1934 in an explosive conflict, forcing them to ally with the Russo family to quell the escalating violence, granting their Don a means of immortality. Ultimately, they fail in stopping the Homuncli faction and lost their trump card Graham Spector to the opposing faction, resorting to Senator Beriam's influence for help. It is eventually revealed that the head of Nebula is Renee, an immortal and one of the alchemy teachers in the 1700s. Their only successful kidnapping of Frank, a homunclus of Huey Laforet, marked the end of their appearance in 1934.

Durarara!!

The company is mentioned in recurring stories at modern times through the series Durarara!! The first act depicts them having bought out Yagiri Pharmaceuticals, headquarters of one of the locals named Namie Yagiri to conduct research on Dulluhan activity among other experiments and manufacturing near indestructible pens that could allegedly stop a tank used by the former's brother Seiji Yagiri. They are also targeting resident supernatural entity Celty Sturluson 's head and eventually succeed in the final volumes of Durarara!! 13. Namie Yagiri is hired to conduct research on the Celty's head after causing a near cataclysmic apocalypse in the city of Ikebukuro and stopped by the the main cast of Durarara. Celty's head is taken to Chicago's headquarters.

Notable Employees and Associates
Senator Manfred Beriam (1930's): A powerful politician searching for immortality to abolish it.

Renee Paramedes Branvillier (1930's): is an immortal researcher using the company to advance her experiments. She ultimately becomes its leader in certain story lines, implied to still lead Nebula to the present Durarara storyline.

Godfather Placido Russo (1930's): The leader of the Russo Crime family, Renee uses them as a means to quell a series of violent acts to their organizational buildings in Chicago by giving the don incomplete immortality. When they fail, they disassociate from the Russo and Placido is consumed by Renee.

Godfather Bartolo Runoratta (1930's): The leader of the Runorata Crime family and appears to be more interested in immortality for the science as opposed to the secret of immortality itself.

Shingen Kishitani : One of their chief scientists when the supernatural is involved. Frequently disregards Nebula's goals in favor of his own frivolous endeavors. Is only affiliated with them for the research funding.

Emilia Kishitani : Shingen's wife and assistant. Share's her husbands interest for the supernatural and the unusual.

Egor (hired mercenary): Hired by Shingen to capture Ruri Hijiribe until she was ultimately rejected for testing.

Nebula Employees (1930s): Their very own employees, 1200 of the staff of Mist Wall in New York were unwillingly granted immortality via vaccine innoculations and were revealed ot have been done so during an orchestrated incident to test the limits of incomplete immortality. It is unknown what became of most of the staff after the incident. It is also unknown if the present storyline employees of Durarara and Etsuna Bridge are granted incomplete immortality discreetly.

Notable Test Subjects or Candidates for Testing
Celty Sturluson : Agreed to testing in exchange for safe passage to Japan. Company has since lost interest in Celty's body and is more focused on finding the head.

Ruri Hijiribe : Considered for testing by Shingen but was ultimately rejected by his superiors due to the belief that she would yield very little new discoveries.

Shizuo Heiwajima : Considered but ultimately rejected as a viable test subject (most likely due to his volatile temper).

Huey LaForet (1930s): One of the Original Immortals. Prisoner held in Alcatraz during the 1930s for an unknown period of time.

Nebula Employees (1930s): Their very own employees, 1200 of the staff of Mist Wall in New York were unwillingly granted immortality via vaccine innoculations and were revealed ot have been done so during an orchestrated incident to test the limits of incomplete immortality. It is unknown what became of most of the staff after the incident.