Sirrus was born in 9434 DE (equivalent to 1777 AD) and is the youngest son of Atrus and Catherine. He lived on Myst Island with his mother, father and older brother Achenar, who is the second antagonist in the series. The family used to do so many things with each other, such as explore the different ages that Atrus had written. This was until Atrus's grandmother, Ti'ana dies. Overcome with grief, Atrus buried himself in his work, leaving no time to interact with Sirrus or Achenar. They saw this as a sign of neglect, and abused Atrus's trust by exploiting the inhabitants of the different ages kept in the library on Myst Island. They would rule over the ages, steal all the riches and then burn the book that linked to that age, then move on to the next. Atrus soon discovered this, and kept the last four books that hadn't been burned in safe places across the island. Both Sirrus and Achenar then tricked their father by lying to him, saying that Catherine was in D'Ni waiting for him. He linked to D'Ni, and they removed a single page from his Myst linking book, preventing him from linking back. They did the same thing to Catherine, saying Atrus was waiting for her in Riven, where she was imprisoned by Gehn. Finally, their greed overwhelmed them. Both Sirrus and Achenar linked into two different ages without realising they were both trap books. They were both trapped in 'one man prisons', as only one person could be trapped in a book at one time.
MystLater that year, a person known only as the Stranger, stumbled across a Myst linking book by accident and without realising, linked to the deserted Myst Island. There, he stumbled across the Red prison book that held Sirrus. He tried to trick the Stranger into finding all the red pages in order for his release, blaming his brother for all the terrible things that had happened. If the player finds all red pages, he will then be imprisoned and trapped in the book whilst Sirrus escapes. He finds Atrus trapped in a green book, who tells him the whole story. He finds the single page and sets Atrus free, who the destroys the Red and Blue books.
Myst III: Exile
A picture of both Sirrus and Achenar is seen on the desk of Atrus's Study in their new home of Tomahna. Saavedro, who is the villain of the game, steals one of Atrus's books, as revenge for what Sirrus and Achenar did to his age of Narayan. He did not realise that Atrus had already dealt with his sons, and once cornered, he gives up the book and goes back to Narayan in peace.
Myst IV: Revelation
Myst IV: Revelation sees the return of Sirrus and his brother. Atrus reveals that his sons did not die when the two books were burned, and they were transferred to other prison ages. Sirrus was imprisoned in the Spire Age for twenty years after the events of Myst. Whilst in Spire, he found a way to manipulate the different elements in the age to create explosives. He then learnt that he had a new sister, Yeesha, who was born just before Exile. He instantly despised her, although he didn't show it and only pretended to love her. He eventually blew up the linking chamber and linked to Tomahna, kidnapped Yeesha and took her to the Serenia Age. His aim was to replace her mind with his, pretend to be Yeesha, learn the Art from Atrus and then kill him. Even though he managed to put his mind into Yeesha's head, he didn't fool the Stranger of Achenar and left Yeesha's body; his mind maintained in the Dream world. He uses Yeesha's memories as an anchor in the world to avoid getting crushed, however the Stranger frees her memories and Sirrus's mind is crushed. As a result of this, he is killed by the rapid changes of the Dream world.