Sirrus was younger than Achenar by 2 years. Their father viewed his sons as the future of D'ni and paid much attention to their education. When Sirrus was just 8 years old, Anna died accidentally. Her death shattered the family. Atrus buried himself in work, spending less and less time with his sons, while Catherine was too consummed by sorrow to see that her sons needed her most. Sirrus must have seen this as rejection, but his pride didn't let it show.
Atrus took the brothers to the Ages he had written. They had been to Serenia as well as Everdunes where they met Pran and her people. He considered teaching them The Art and to that end he wrote the Lesson Ages to experience its principles and employed Saavedro to teach them the principles of interdependence in Narayan. That was around the year 9445.
Their biggest adventure was in Channelwood where they socialized with the Tree-dwellers, and picked their language fast. When Atrus had to leave for Osmoian, Sirrus insisted to let them stay; Atrus reluctantly consented, with the warning not to take advantage of the respect the creatures had for them. During the following 3 days, the brothers constructed a boat with the creatures and explored the surrounding waters. When Atrus returned, he said that their old friend Pran had died, and he and their mother suggested that they should leave for a while. The brothers were made enthusiastic by their experiences and asked to return again, or explore some other Ages alone.
To his excitement, Atrus brought Sirrus to Rime to help with the Crystal Viewer. Sirrus enjoyed the cold and ice and was intrigued with the crystals they brought. After the shaft and an observation post were completed Sirrus was consumed with studying the crystals of and the Ages inside of the book that appeared. After much experimenting with the crystal shapes, a nearly perfect view of an Age appeared, and the brothers were excited that they could see Channelwood or Stoneship.
Sirrus started to feel much pressed by their father and, ignoring his warnings and instructions, decided to sail away from the Fortress, towards the Black Ships territory to escape. He threw to the sea his father's journal which Achenar was reading. Eventually, the Black Ships found the brothers and confiscated their boat. They were taken before the Ebony Cardinal, who seemed interested to hear that the captives were the sons of his enemy, the Atrus. Sirrus saw an opportunity, and had a proposition for him, in exchange for safe passage through their waters, knowing that this would give themselves freedom away from their father. Sirrus was enchanted by the lifestyle of the pirates and their luxury and he helped them upgrade some of their technologies with knowledge he had from hs father. The Ebony Cardinal then accepted them for the bond of initiation and be his sons. Sirrus almost had a slave killed for spilling his wine.
During those days, Sirrus had thoughts that if they possessed their father's books. He planned to return to Myst and take all the books with them. Then they'd destroy the books in Camder so that Atrus would be stranded there. Then they'd lead the Black Ships to other Ages and utilize them to become their masters.
While they were missing, their parents were worrying about them so when they returned to the Fortress, they were scolded before taken back to Myst. There, Sirrus stole a Linking Book from the Myst Library and brought it to the Ebony Cardinal.
Reign of terror
It was 5 years after their meeting with Saavedro when the brothers decided to return to Narayan. This time Saavedro noticed that they seemed not only grown but also darker. They promised to "fix" their world with the Art (which they actually didn't know) so that they won't have to work on the Lattice Tree for their whole lives. Apparently Saavedro initially believed the promises and helped introduce them to his society. But they started speaking against the old traditions and instigated a rebellion of the youth, persuaded them to refuse caring for the Tree which eventually brought an imbalance to the Age.
As the Age was collapsing by war and imbalance, the brothers left to J'nanin with loot . Saavedro followed them through the linking book and begged to keep their promises. The brothers lured him inside a tusk where they waited for him. They beat him severely and tied him up to a reflection pole. They explained that they didn't intend or know how to fix Narayan, but only to salvage what was worth taking from his world that was "easy pickings". Lighting a bonfire, they linked away, leaving behind the Myst linking book to burn in it. Saavedro was left alone to die, with venomous snakes, but he somehow survived.
The experience on Narayan becomes the template for the brothers's later crimes; they begin subjugating and plundering Atrus's Ages. While Atrus was buried in his work, the brothers exploited their father's Ages, specifically Channelwood, Mechanical, Stoneship and Terrell. They ruled jointly as tyrants and gods, plundering, enslaving and exterminating. Sirrus's personal spaces in each Age are opulent and luxurious, betraying his elegant and also megalomaniac nature. When the Stranger visited the Ages years later, they were all deserted, and most of the books in the Myst Library were burnt. Atrus had noticed it but didn't know which brother was responsible and left a distress message to Catherine and salvage some of them.
Eventually the brothers decided to get rid of their parents. They lied to Catherine that Atrus for some reason went to Riven, so after many years she used the forbidden Green Book for the first time. When Atrus also came, they told him the same. Knowing that Atrus would take with him a spare linking book back to Myst, Sirrus left a message for Achenar in his Channelwood imager reminding him to sabotage the book by taking only one page, so that he was unable to return and would be stranded.
He builts a bonfire before proceeding and soon realizes he had been fooled by the linking panel. His first plan was to reach the ground to find the linking book to Myst that his father should have dropped, unknown that he had let it fall into the abyss as Spire was, in fact, a prison Age. He camps near a vegetal cavern in order to have easy access to food. In his attempt to find the ground, Sirrus follows some "windpipes" that lead only to caverns full of crystals with odd properties, which he begins to study.
In the meantime, a few months after his arrival, a Stranger links to Myst and soon after in Riven, rescuing his parents. Atrus realise the dark role of his sons and what happened to them, and decides to dispose the two prisons books so that no other is trapped in them.
A year after his entrampment there, Sirrus notices flickering lights in some of the far away floating "palaces" and decides to explore there in case it is inhabited, even if Atrus didn't intend to, like Stoneship. To that end, he considers using making a "rock-ship" out of the floating phosphorescent green rocks, using their strong diamagnetic properties. While working, Sirrus was admiring the storms raging in the second cloud layer from the safety of his shelter, amazed by the wonder of Spire and regretting for not been taught the Art.
For the following 3 years Sirrus dedicates himself to his experiments and constructions, even without writing in his journal. He notices that the crystals not only store energy like batteries but also produce sound when it is released; attaching them to floating rocks and harnessing energy from charged clouds, he employs them as electromagnet. During a brewing storm, Sirrus charges his first conductor. His first rock-ship breaks free because of not having enough conductors, so he repeats his experiment with more conductors; he also installs an electromagnet in the roof to counterbalance their stronger pull.
In the following years Atrus continues to check upon his Prison Ages, using the Crystal Viewer in Rime, and considers improving the device, and also make one adaptable to Tomahna and manages to get images from Spire and other Ages with it. Catherine nonetheless expressed to him her wish to meet their sons in person. Atrus finally saw the devices Sirrus was constructing and was amazed to see that he was following his steps.
Five years into his entrapment in Spire, he uses his rock-ship to go and harvest more crystals. Soon after he notices a nara Linking Chamber that would have been written there only through the Art, and realizes for the first time that his father is alive after all. Indeed, Atrus finally listened to Catherine's pleas and wrote this structure to be able to meet in person after years. During one of these meetings, Atrus expressed his bitterness for what Sirrus did and didn't want to listen about his scientific accomplishments. In the following meetings Sirrus acts repentant, not convincing Atrus but softening Catherine. To touch more on her sensitivity, Sirrus starts making a sculpture.
Considering that the linking chamber is from nara, Sirrus plans to use his acquired knowledge on frequency and molecular vibration to break it, and employs his organ. He dismantles parts of his rock-ship system and rewires the conductors into the throne to get more power to the cables. In the meantime he learns from his parents that he has a sister.
In order to perform his experiments, he tries to chip off nara pieces from the chamber but he is unable. He steals one of the chess pieces that his parents brought to play with him.
The next year he meets his sister for the first time, who studies him with curiosity. Sometime later he destroys his lab during his frequency tests. He continues to remove the walls of the old crystal cavern for safety.
He became furious when he learns from Yeesha that Atrus began teaching Yeesha the Art yet always denied to teach him.
Soon after he finds the correct frequency to break nara. He proceeds with his plan to break it with a bomb. He links to Tomahna and soon after he links to Haven to find his brother and he attacks him.
Sirrus's main charateristic is luxury and greed, if not megalomania; his manners show some aristocratic elegance, in contrast to his brother's. His demeanor can be described as snotty. His private spaces in the remaining Ages are characterized by opulence, with exquisite furniture, beds, cloths, decorated with ornaments. In one of the drawers in Stoneship one can find syringes and drugs, suggesting that he made use of substances.
- Clarified by Richard A. Watson
- Serenia Journal
- Catherine's Tomahna Journal
- Myst III: Exile
- Saavedro's Journal
- Channelwod Journal
- Myst Soundtrack booklet
- First Rime Journal
- Second Rime Journal
- Mechanical Journal
- Myst comic: The Book of Black Ships; note that Sirrus is called Achenar there.
- Myst III: Exile - Prima Official Guide
- Saavedro's Journal
- Pool Imager message
- Sirrus's Garden Journal
- Atrus's Tomahna Journal
- Sirrus's Bomb Factory Journal
- Myst 4 flashback scene