“You're not supposed to be in here! You're going to ruin the surprise!”
The following article/section contains spoilers.
The being known by the Ostrons as 'the Unum', and to ignorant offworlders as 'the Wall', has a reputation for prophecy. Those wealthy enough to own moons have journeyed to Cetus, hoping to buy an audience. But the Unum has no use for wealth, and she alone decides who will hear her words, and when.
Ostrons believe she sits at the pin-center of the universe, listening to the infinite poetry of cause-and-effect.
Some visitors to her chamber leave bitterly disappointed, others elated, others furious. But one thing is certain: the information she imparts changes the person who receives it.
—The Unum Fragment
In the dying days of the Orokin, with forums and promenades still blood-wet from Tenno betrayal, a colossal Sentient descended upon ancient Er, falling from distant stars to deliver upon Orokin a terrible and final ruin. Tower upon Tower fell to its weapons, but one withstood. The Tower of the Unum.
The Unum is suggested to have some forms of prophetic abilities. It is said that many rich, powerful, and influential people had traveled to Cetus and were willing to pay a fortune to seek an audience with her, but the Unum would only commune to those she wishes, regardless of their status or wealth.
Whatever information she provides, it is certain that it changes whoever hears it, such as Onkko. Before he became a Quill, the former Cetus archivist had probably received a vision about Saya's avoidable demise from the Unum, leading him to leave her in Konzu's care.
The Unum's Tower[]
Concept art of the Ostrons harvesting Unum's walls
As the tower is made out of living flesh, the Ostrons use explosives to selectively harvest her biologically regrowable walls, under her permission and direction, to provide meat for their families and collect the blood, Temple Kuva, for other uses. Leftover shells of the walls are also used as building materials.
The interior of the Unum's tower is also harvested, and holds various markets and stalls where the Ostrons sell their wares. Numerous tunnels have been carved and drilled out, leading to the various floors and chambers of the tower.
She is also responsible for the energy wall that envelops the Plains and keeps the Eidolons contained, and her influence protects the Ostrons' home, Cetus, from outside dangers such as the Grineer. Anyone approaching the settlement with hostile intentions would find "their transmissions silenced, their engines turned cold, and their weapons reduced to lumps of dead iron."
The Tower of Unum was one of, if not the last Orokin Tower to survive when, in the later days of the Old War, a single powerful spectral Sentient managed to land on and lay waste to Earth, the heart of the Orokin Empire. When the Tenno betrayed the Orokin, Gara stayed to protect the Tower from the Sentient.
The creature was blinded by the daylight, so it hid amongst the shadows during the day and struck the Tower at night. In desperation, the Unum instructed her followers to give her blood, Temple Kuva, to the animals living on the plains, so she could connect to them and use them to find where the Sentient was hiding and kill it before it could destroy the Tower.
The Unum's attempt backfired; the Sentient captured some of the animals and realized that the Tower's blood could restore its procreative ability, which the entire Sentient race had lost upon traveling through the Void. With this realization, the Sentient then assaulted the Tower with all of its might to seize control, replacing the Unum, and thus gaining the power to rebuild its entire race once again.
To prevent this unthinkable catastrophe, the Unum used a powerful energy barrier to trap the Sentient and gave Gara a devastating energy bomb, created from her flesh. Sacrificing herself, Gara successfully destroyed the Sentient's heart in one final battle. In the aftermath, countless pieces of the Sentient scattered about the neighboring Plains. These ghostly fragments, the mindless Eidolons, currently litter the region, appearing at night to hopelessly roam in an attempt to rebuild themselves.
The Unum instructs Onkko to give Nakak a mask, fitted with unique lenses. Over the course of the quest, the Unum provides Nakak with visions of what happened to the Warframe known as 'The Warden' who would later become Revenant.
As the Sentients invaded the Origin System, they targeted the Unum's Tower and crashed a Murex into it. They deactivated the Unum and plundered her Temple Kuva. Concept art of the Narmer Veils suggest they are constructed from the Tower's flesh and materials.
The Tenno, following a vengeful Lotus, arrived in Cetus and made their way into the Tower with Konzu's help. Just as they reached the top, the Murex retreated from the tower. The Tenno awoke the Unum, who stopped time in the general vicinity to allow them to reach the Murex before it departed.
Trivia[]
A piece of harvested wall can be seen being transported down to Cetus during the introduction cutscene when Tenno enters Cetus for the first time.
Tenno can watch the meat extracting process, on the beach near the landing pad, every time they enter Cetus.
Players can also purchase tower meat as an Orbiter decoration.
Harvesting the Tower with explosives releases gold dust that, when breathed in, can cause a pulmonary disease known to the Ostrons as gilded lung[1], which appears to be based on the real-world disease Silicosis.
Old Man Suumbaat is suggested to be suffering from this disease, as he can be heard coughing and retching from time to time.
Concept art reveals that the Unum extends almost as deep into the earth as it is tall. The purpose for this is currently unknown.
The Orokin ruins in Earth Proxima resemble the Unum, implying that towers like the Unum are mobile.
Since the Void tileset is essentially inside the Orokin Towers stationed to observe/research the Void, it can be assumed that these towers can serve as space stations as well.
Gara stayed to protect the Tower from the Sentient.
Revenant.
