Tripod's Nest: the Corruption growth that housed the Sprawl's Tripods

The Tripod's Nest was a large formation of the Corruption that grew in the Fuel Mega Storage area of the CEC Facility on Titan Station, shaped into a nest that accommodated a population of Tripods. It sat in the middle of the station's industrial heart during the outbreak of 2511, blocking a monorail line that Isaac Clarke needed in order to reach the Government Sector with Ellie Langford and Nolan Stross. Isaac cleared it by using his Kinesis Module to throw explosives into the fuel tanks around it, and the resulting fire consumed the nest, the Tripods living in it and most of the facility that held them.

A structure grown rather than built#

The Corruption is normally described as an encrusting mass, a sheet of reanimated tissue that spreads over bulkheads and floors wherever a Marker signal reaches. Analysis aboard the USG Ishimura three years earlier had characterized it as something closest to a bacterium with viral behaviour, infecting dead cells through osmosis and then reproducing asexually at an extraordinary rate, one organism multiplying twentyfold in a minute. That growth rate is what allows the Corruption to smother a ship faster than crews can burn it back.

The Tripod's Nest was that same tissue doing something more organized. Rather than simply coating what it reached, the mass in Fuel Mega Storage was formed into a nest, a structure of a particular size and shape built to hold a particular kind of animal. The Corruption had already been documented as a habitat: Guardians, Cysts and Nests cannot form without it, and it supplies both the substrate they anchor to and the ready biomass they draw on. Fuel Mega Storage showed the same principle applied at the top of the scale, with the habitat sized for the largest walking forms the outbreak had produced.

Where it stood#

Fuel Mega Storage sat inside the Concordance Extraction Corporation's base of operations on Titan Station. The facility housed heavy machinery and the station's sophisticated fuel storage, ran at around seventy degrees centigrade on average operational cycles, and admitted its workforce through a security door and a scanning line. Its most significant structure was the shipyard and the fuel storage area surrounding it, and it was in that shipyard that the Ishimura itself lay docked, still under the clean-up operation that had followed the loss of Aegis VII.

By the time Isaac reached it the facility was badly affected by rampant strains of the Corruption and swarming with Necromorphs. Guardians had grown out of various bulkheads. Stalkers and Slashers worked the catwalks. Fuel Mega Storage was the deepest point of that infestation, and the nest was the thing the infestation had been building toward.

The residents#

A Tripod is not a converted individual. It is a compound form assembled from numerous hosts, comparable in size to a Brute and standing on three legs, with a bladed tongue slung from a malformed head that on close inspection turns out to be a man's head twisted upside down. A single specimen typically incorporated six bodies: male hosts for the arms, the leg and the head, a female host for the stomach, and an infant for the tongue blade.

Tripods were violent even measured against other Necromorphs. They swung their arms in wide arcs, slammed their fists into decking, flailed the bladed tongue, and pounced across open ground from surprising distances. Their vulnerable points were three yellow pustules, one on each arm and one on the tongue, and they did not go down until both arms were taken off them. They were almost always encountered in large, open, roughly circular spaces, which is precisely the shape of the area the nest occupied.

The fight at Fuel Mega Storage#

Isaac entered the CEC Facility because the destruction of the station's transport hub had left him no other route. He was moving with Ellie Langford and Nolan Stross, and he was heading for the Government Sector, which meant reaching a monorail line that ran out of the industrial district. The nest and its Tripods held that line.

He did not clear it by attrition. The room was ringed with fuel tanks, and Isaac used Kinesis to pitch explosives into them while the Tripods came at him. The detonations killed the resident Tripods, destroyed the nest itself, and opened the monorail route to the Government Sector. It was the last time Tripods were encountered on the station.

What burned with it#

The cost of the demolition was the facility. Much of the CEC Facility was destroyed when the battle at Fuel Storage incinerated its fuel reserves, taking the machinery, the storage lines and the surrounding structure with the nest. What remained afterward stood only until Titan Station's nuclear reactor detonated with the catastrophic failure of Project Telomere, at which point the whole district ceased to exist.

The nest is worth noting for what it says about the Corruption's role in an outbreak. The growth is not incidental damage. It converts atmosphere into noxious gas in concert with Wheezers, it grows through corridors and ventilation runs in a way that seals escape routes while spreading itself along an existing network, and it holds a standing supply of biomass for recombination. At Fuel Mega Storage it added one more function to that list, sheltering and supplying the heaviest walking forms the station had produced. Destroying the nest destroyed the Tripods with it, which suggests the relationship ran in both directions.