Several transport tubes and shuttle rides later you reach G-24, in Middle Tier. This section of Tribon is a huge cavern blasted from the planet's rock. Tubeways criss-cross above you, between massive support struts and a dizzying array of structures built atop each other with no obvious rhyme or reason, like a coral excresence made of steel, stone, glass and neon. No less densely populated than the Downport, the "street" bustles with sentient life and the air feels dead and smoky.
The Black Nebula is located in a spur of rock that juts out from one of the cavern walls. It has been dug into and shored up with metal gantries to form a sort of natural multi-storey building, and the Nebula is on the ground floor.
Inside, the club is fitted out in expensive style, a dark ceiling studded with starlights, a huge curving neon-rimmed bar that imitates the rock spur that the Nebula is carved from. The club is at about half capacity with patrons of all species enjoying the show - music performed by a human woman backed by a grome band. Holographic dancers gyrate atop podium-projectors. Beyond you see a gaming area with all manner of gambling on offer. Hulking balosian bouncers guard the door. Several vending machines around the walls offer "Quality Oxygen" for a price.
Working behind the bar you spot a male abbai, matching the description of Traven, your contact who is supposed to know how you can get your hands on some Tal-kon'sha technology.
OOC: The pic is from the original adventure, where Traven is a mutant human with a fishlike appearance. I figured an Abbai was close enough...
Balosians are kind of the Gammorean Guard of B5. I've not found any official depiction of them apart from being tough and often employed as thugs, so I'm assuming them to be the hulking alien types often shown in Season One. If you have access to the shows, there are some guarding n'grath's room in Soul Hunter, and a similar species is rented out to G'kar by n'grath as a bodyguard in Parliament of Dreams. Possibly one tries to throw Sinclair and Londo out of Ock's bar in Born to the Purple, I can't recall what that one looked like. Basically, big, bulky and with a sort of rhino-horn effect on the nose. That's your balosian.