Feros

Description
The ExoGeni Corporation has founded a pilot colony on Feros to explore the Prothean ruins that blanket two-thirds of the planet's land mass. The atmosphere is fouled with dust. Terrestrial travel is hampered by crumbled debris dozens of meters deep. There are indications that Feros was a much colder world in the past. Feros has two large moons, Orcan (the farther) and Vardet.

Codex Entry
Two-thirds of the habitable surface is covered with the ruins of crumbling Prothean megatropolis. In the millennia since the Prothean extinction, the ruins have been picked over by looters many times.

Feros was considered a poor prospect for colonization, as little open ground remains for agriculture. The only sizeable fresh water sources are the poles, which are tapped by the decaying Prothean aqueduct system. The dead cities, while in good condition considering their antiquity, are of uncertain stability. Ground level is congested by a dozen meters of fallen debris, and the air is fouled by dust. Feros also has two large moons, Orcan and Verdet.

In 2178, the human ExoGeni Corporation announced its intention to place a permanent colony on Feros, to thoroughly explore the ruins. The pioneer settlement was placed on the upper levels of the several intact skyscrapers, using the surviving Prothean aqueducts and rooftop hydroponics gardens to support the population.

Plot
"T-there's nothing here to warrant an invasion! There's barely enough here to warrant a colony!" - Ethan Jeong

Zhu's Hope
Following reports of geth attacks and a breakdown in communications, Commander Shepard heads to Feros. The Normandy lands at Zhu's Hope, a small port. Upon going ashore, Shepard's squad is met by David Al Talaqani. He tells them to speak to Fai Dan, their leader, before being killed by a geth trooper as a small party of geth rushes the docking bay. The squad destroys them and heads into the colony. Most of Zhu's Hope is centered around a crashed freighter called the Borealis that the colonists are using for shelter, at the foot of one of the ancient towers. Shepard finds Fai Dan talking to Arcelia Silvia Martinez, but their conversation is interrupted by another geth attack. They've taken control of the nearby tower. Shepard fights them off, then leads the squad up to to the roof where a geth dropship is dropping in reinforcements. After they kill the geth ground troops, the ship departs, and Shepard reports back to Zhu's Hope.

Fai Dan tells them that the colony is in a bad way. They were really beginning to grow something special here, but the geth attacks are relentless. Shepard asks what the geth are after but Fai Dan has no idea. ExoGeni Corporation founded the colony here, exchanging funding for the colonists handing over any useful finds, but Feros doesn't have many resources. The geth seem to be holed up in the ExoGeni headquarters, easy to reach on the old Prothean Skyway. Fai Dan explains that there are still geth in the tunnels below the tower, and Zhu's Hope has other problems - they are short on water, power and food.

Shepard asks around the colony, to find out what the squad can do for them, but something seems a little off. The colonists are fine when Shepard offers to help them out, but as soon as the conversation turns to the colony itself, they become evasive or rude, and keep saying: "ask Fai Dan about that". Fai Dan claims the colonists are shellshocked from the constant attacks; many of them have lost friends or loved ones. Shepard doesn't have time to dwell on it, and descends into the tunnels. The squad finds resources the colonists can use and kill the geth, but while they're in the tunnels Shepard meets a man called Ian Newstead who seems to have lost his mind, talking strangely, laughing and screaming in pain. Upon returning to the surface Shepard asks Fai Dan about him, but he just says Ian is sick and there's nothing they can do. Now Zhu's Hope is stable, Shepard heads out to the geth base at ExoGeni in a ground Mako.

ExoGeni and the Geth Base
As they travel up the Skyway, which is patrolled by geth armatures, the squad picks up radio chatter but can't pinpoint the source. Up ahead they see a geth dropship that appears to be attached to one of the towers. Passing a weigh station, they finally home in on the signal and find another group of colonists hiding under the Skyway, led by Julianna Baynham and an ExoGeni rep, Ethan Jeong. They confirm that the geth are in the ExoGeni headquarters, but Julianna is more worried about her daughter, Lizbeth Baynham, who was last seen in the building. Once they reach the ExoGeni building, Shepard sees the geth have set up energy fields to cut off key access points. The squad get inside by dropping in through the basement but almost get shot by Lizbeth, who was hiding nearby. She tells them the geth ship is powering those energy fields with giant claws that are anchoring it to the building. While the fields are up, they're trapped in here. Shepard asks if she knows what the geth are after, and Lizbeth suggests it might be the Thorian, a plant ExoGeni was studying.

Going upstairs, Shepard finds a krogan interrogating an ExoGeni VI. Once the krogan has been taken care of, the VI tells Shepard more about the Thorian. It is a sentient plant with mind-controlling abilities. Shepard blinks when the VI goes on to explain about the 'Zhu's Hope control group'. The Thorian, which is located under the colony, releases spores that turn humans into thralls to serve it, explaining the colonists' strange behaviour. ExoGeni allowed this to happen to study the effects. Shepard's squad clears out the geth in the building, arriving at the shuttle bay where they use a malfunctioning door to shear off one of the dropship's claws. The ship falls from the tower and the energy fields drop. Once communications are restored, Shepard gets a call from an anxious Joker, warning that the colonists have suddenly turned violent. They're attacking the Normandy. Shepard can tell Joker to safeguard the ship or point out the colonists can't do any real damage, and says they're on their way back.

Lizbeth meets them outside the building, confessing she was too afraid of ExoGeni to stop the experiments. Another call from Joker warns of increased geth activity on the Skyway. Shepard takes the Mako down the Skyway and deals with the geth, but they hear radio chatter suggesting Julianna is in trouble and stop at the weigh station. Jeong is irrational, threatening Julianna and saying ExoGeni is going to purge the colony to hide their studies into the Thorian. Shepard has to deal with him, before Julianna asks how Shepard is going to get to the Thorian.


 * N.B.: Keep in mind that when doing the Feros sidequests, if you kill the colonists who gave you the quests, you'll be unable to complete them.

Julianna says the colonists will never let Shepard near the Thorian and will die to protect it. She offers an alternative, gas grenades that will knock the colonists out without hurting them. Taking the grenades, Shepard goes back to Zhu's Hope, only to find the colony crawling with Thorian Creepers. Killing the creepers and dealing with the colonists, Shepard uses a crane to lift one of the freighter's pods and reveal the entrance to the Thorian's lair, only to be confronted by Fai Dan. The spores are forcing him to attack Shepard - he refuses to do it and shoots himself instead.

The Thorian
Shepard leads the squad underground, but they are stunned at the sight of the Thorian towering over them - "...we are gonna need bigger guns". The Thorian disgorges an asari clone to speak for it. According to the Thorian, Saren made some sort of trade with it for knowledge, but then the geth came and started killing the colonists, its thralls. It refuses to listen to Shepard and attacks, sending waves of Thorian Creepers and asari clones after the squad. Shepard destroys the Thorian's neural nodes one by one. The Thorian's tendrils snap; the creature is dislodged and falls through the ruins, dead.

An asari is freed from its grip, introducing herself as Shiala, a follower of Matriarch Benezia. She says Saren came here looking for the Cipher, the ancestral knowledge, culture and experience of the Protheans. Without it, the vision from the Eden Prime beacon does not make sense because it was intended for a Prothean mind to interpret. The Thorian was here when the Protheans lived on Feros; it studied and even absorbed a few of them. Shiala was 'sacrificed' to the Thorian by Saren to get the Cipher, but Saren knows Shepard is following him. Once he had the Cipher, the Thorian became a liability and Saren ordered the geth to destroy it. Shiala uses her biotics to touch Shepard's mind and give the commander the Cipher - the experience is debilitating, and the concerned squad members say they should get Shepard back to the Normandy.

On the way back, they pass through Zhu's Hope. Now the Thorian is dead, the surviving colonists are recovering from the spores and have been reunited with the Skyway group.

Trivia
The mission on Feros - an endangered colony, alien infection, a corporation getting in over its head, a group of marines using an APC, a female survivor in hiding - recalls the sci-fi movie Aliens. The planet might also be named after the dropship pilot in Aliens, Corporal Ferro; and its colony after Hadley's Hope.