When The Book of Atrus begins, Gehn, then 19, is stamping around the garden his mother has made in the Cleft, muddying up the pool of precious water and ruining the delicate plants. He had married, and his pregnant wife had become very ill. In desperation, as a last resort, he brought her to Anna, but it was too late and the girl died giving birth to Gehn's son. In a fury of anger and despair, Gehn left his infant son with his mother, not even bothering to name him, and disappeared.

The book then jumps ahead in time and takes us through a series of little vignettes showing the life that Anna and Atrus (for Anna has named him after his grandfather) lead together. She has spent the years teaching him well. Anna has taught Atrus to see "the whole," all sides of things. She's trained him to be thorough, to take his time and do things well. She's told him stories of the D'ni all his life. She's taught him their spoken language and their common written language, but hasn't begun training him in the special language of the Art, feeling that's he's too young. He's never known any other place or way of life, and his temperament is very much like hers, so he's content with their life together.

When he is fourteen, Atrus conducts an experiment within the crater of the volcano. He hopes to be able to charge a battery he's made so he can automate the drawing of water, which would make things easier for them. While trying to charge the battery, there is an explosion, which uncovers a cave or tunnel of some kind that looks almost as if it had been carved from the rock. Before he can investigate, his grandmother calls him away, telling him to leave the battery as it is just too dangerous down there in the crater.

Later when Anna isn't watching, Atrus returns to retrieve his battery and to investigate the tunnel. In the tunnel he finds a huge carving in the wall - a D'ni word! Now he's really excited! Up until now he's only half-believed the stories his grandmother has told him about the D'ni. He also finds a fire-marble in the tunnel. He hurries away, meaning to raise his battery before his grandmother notices he's gone.

Anna finds him while he is dragging the battery to the Cleft and helps him move it the last of the way. She doesn't scold him, though he has disobeyed her, but tells him it is time she told him a story. Then she tells him about the Fall of D'ni and Ti'ana's role in it, but doesn't tell him that she is Ti'ana.

"... and so, when Veovis finally returned, the fate of the D'ni was sealed. Within a day the great work of millennia was undone and the great caverns of the D'ni emptied of life. and all because of Ti'ana's misjudgment." (Anna said)

Atrus was silent a while, then he looked up at Anna. "So you blame Ti'ana, then?"

She nodded.

"But she couldn't have known, surely? Besides, she did what she thought best."

"To salve her own conscience, maybe. But was it best for the D'ni? There were others who wanted Veovis put to death after the first revolt. If their voices had been listened to... if only Ti'ana had not spoken so eloquently to the Great Council..."

Anna fell silent again, her head lowered.

Atrus frowned, then shook his head. "I didn't know..."

"No..." Anna stared a moment longer at her hands, then looked to him and smiled. "Nor does it really matter now. All that is in the past. The D'ni are no more. Only the tales remain."

Atrus tells her about the fire-marble and where he found it. At the sight of it her whole countenance changes. She tells him not to go there again. It is very dangerous down there and he isn't ready yet. She makes him promise. He does and keeps it.

After that she mentions to him the ideas behind the special D'ni language used in The Art, and thinks about being able to teach him soon, but before she can begin, Gehn comes up out of the volcano. He has been living in the ruins of D'ni and has returned to claim his son. In spite of Anna's protests, Gehn takes Atrus with him down into D'ni, leaving her behind.

On the way down Gehn constantly consults a notebook. Noticing this, Atrus develops a deep respect for him, thinking of how Gehn must have spent a long time alone in the dark, braving great dangers, searching out the paths to find his goal. The way was so complicated, that he had had to record the directions in that notebook. The trip is torturous, long, and dangerous. There are great beauties as well as dangers. At last, foot sore and very weary, they reach D'ni.

We are treated to a fascinating picture of the vast ruins of D'ni. We learn all sorts of interesting tidbits of D'ni culture. Because The Book of Atrus was published a year before The Book of Ti'ana, many people read it first. After reading The Book of Ti'ana, and then reading The Book of Atrus again, many of the things that Atrus sees in D'ni make more sense.

At first Atrus thinks his father is wonderful. He has a strong case of hero worship. He rationalizes Gehn's bluntness and rudeness by thinking that he's not been around people for so long, that he's lost his manners. But Gehn is more than merely blunt. He's impatient, dictatorial, arrogant, and easily offended. He frequently jumps to wrong conclusions in many matters and is difficult to please.

Gehn eventually tells Atrus that Anna is Ti'ana and that the Fall of D'ni was indeed her fault. His version of the story is as flawed as everything else about him, but it has an affect on Atrus. For a while Atrus is angry with Anna for not telling him, but over time he comes to his senses and begins to see the "whole" again and understands what Anna had tried to teach him. Understanding this gives him a better understanding of The Art of Writing Ages.

Gehn has taught himself enough of The Art to write Ages, but they are always flawed and unstable. He is sure that there are magic formulas for the Writing and feels that if he just gets the right combination of phrases copied out of other Descriptive Books, he'll be able to write stable Ages. He doesn't realize that you must look at the big picture, or that you must plan and write with an understanding of the smallest details and with great care.

After a few years, Gehn takes Atrus to his 37th Age, secretly hoping that when Atrus studies it, he'll find out why his Ages are always unstable. Gehn experiments a lot, making drastic changes in the Age in an attempt to save it, but it just keeps getting worse.

Meanwhile, he's given Atrus the opportunity to write his first Age. Atrus writes a beautiful stable Age, which he names Inception. When he and Gehn inspect it, Gehn is impatient to return to D'ni and Write more Ages. He doesn't want to stay and explore at all. He doesn't value the Age itself. Gehn doesn't value or even name his own Ages. He merely numbers them. He tells Atrus they have to return for a Korfah V'ja ceremony.

Back in D'ni in his library on K'veer, Gehn tells Atrus the ceremony is for a new god, a god-crowning ceremony. He claims that they are gods, because they create worlds. He says that the people of Age 37 need to be reminded of that. He's been writing in the Descriptive Book for that Age again, making more drastic changes. When Atrus questions what he's doing, Gehn bursts into a rant.

He criticizes Atrus because out of all the notebooks on Ages Atrus was keeping, only one was thorough enough to be a proper Age, and then in the same breath, he criticizes him for sticking to the conventional kind of writing and not experimenting and writing more quickly. He contradicts himself and confuses Atrus, who wonders what his father wants, stable worlds or quick worlds.

"Gehn huffed, exasperated. "You are no good to me if you work at this pace all the time. I need Ages. Dozens of them. Hundreds of them! That is our task, Atrus, don't you see? Our sacred task. To make Ages and populate them. To fill up the nothingness with worlds. Worlds we can own and govern, so that the D'ni will be great again. So that my grandsons will be lords of a million worlds!"

Gehn hurries Atrus off to Age 37, where he's arranged for the Korfah V'ja ceremony. As soon as they link in, they realize that something has gone terribly wrong. Gehn has ruined the Age. The world is falling apart. All the people, Atrus' friends and acquaintances, are going to die. The frightened people beg Gehn to help them. Gehn rushes them through the ceremony and then leaves the Age with Atrus following behind.

Back in the library on K'veer again, Atrus nags Gehn to fix Age 37, as Gehn claimed he could. Gehn crosses out enough of the changes in the Age to take it back up the tree of possibility, so that the Book now links to a different, but similar Age. He didn't fix anything in the damaged Age, he just changed the link to another Age. Atrus goes to see the new Age and comes back knowing the truth.

When he returns to his father, he finds him drugged on that pipe he smokes. Atrus is really angry and yells at his father. In his anger, he says that all Gehn's Ages are unstable, because he doesn't understand what he's been doing all these years, he doesn't understand the "whole."

Gehn becomes furious at his son's words. They hit home too well. He yells at Atrus that he, Atrus, is the one who doesn't know what he's doing. He says that Atrus couldn't possibly learn to Write in three and a half years. He says that he, Gehn, has been studying for thirty years, since he was four.

He takes Atrus' Age, Inception, and begins criticizing how it's written, and then he takes up the pen and starts crossing out what he calls unnecessary phrases. He thinks that Atrus has gotten them all out of books, but Atrus has written it from scratch by himself, a concept that Gehn doesn't begin to understand. Atrus is horrified at what Gehn is doing. He begs him to stop, but Gehn is unstoppable. He ruins the Age. Looking coldly at his son, Gehn accuses Atrus of being like his grandmother, headstrong and inclined to meddle.

Atrus tells Gehn that he had claimed to fix the 37th Age, but instead he had changed the link to a different Age and really fixed nothing. He asks Gehn to let him, Atrus, fix it. Gehn contemptuously says the Book is defective and throws it into the fire. The link is lost and his friends will perish in the terrible destruction that Gehn has caused in their Age.

Atrus is stunned and heartsick. He has learned that his father is mad. He doesn't know what he's going to do, where he's going to go, but he knows he can't stay with Gehn. He decides to say goodbye to him rather than just running away like a child with his tail between his legs.

He finds Gehn in his study heavily drugged with his pipe, and there just beside his father's outstretched hand is the notebook he was always consulting on the way down into D'ni. Curiosity overcomes Atrus' feeling that it would be wrong to look at it. He takes it up and opens it to the first page, reading what is written there, "The Book of Atrus..." At first he is confused, but then he realizes that it refers not to himself, but to Gehn's father.

"He read on, then stopped, the last thread that had connected him to his father broken in that instant. Slowly he sat down in Gehn's chair, nodding to himself, a bitter laugher escaping him."

"There he'd been, admiring his father, exalting him almost, for his courage, his patience in finding a path through the darkness of the tunnels back to D'ni. And all the while the path had been clearly marked, here in his grandfather's notebook. It wasn't Gehn who had taken the risks, but Gehn's father."

Under the painful weight of his disillusionment, Atrus takes the notebook, the Book of Atrus, and leaves K'veer. He tries to make it back up the tunnels to the surface to where he had left Anna nearly four years before, but Gehn's paranoia has served him well. He has removed a crucial page from the notebook and kept it locked in a metal box in a locked drawer in his desk. When he realizes that his son is gone, Gehn summons his servant, Rijus, and they pursue Atrus, catching up with him in the tunnels. They return him to D'ni and lock him up in the deepest room in the island mansion of K'veer.

There seems to be nothing in the room but a desk and the Descriptive Book of Gehn's Fifth Age. Atrus thinks this is a trap, so he leaves it alone and searches for secret passages or a way out, but can't find any. He does find an old stonecutter and using the blade from it, he makes a crack in the wall by the locked door. Instead of freeing him, it brings down the pillars and ceiling in that part of the room, trapping him there.

Turning his attention back to the desk and the Book of Age 5, Atrus wonders why Gehn left the Book there. What does he want? Why did he leave him pen and ink, and a linking book from Age Five back to this room? He realizes that Gehn never does anything without some self-serving reason. Though he now has little choice, he decides to read the book before he visits the Age.

"For several hours he sat there, slowing leafing through the pages, noting all the flaws, all the possible contradictions that Gehn's particular writing style threw up. More than ever, he could see his father's limited vision on every page, like a hideous tapestry quilted together from exquisite patches of silk. The entire work was shortsighted and disjointed and yet it was also, paradoxically, quite clever. Surprisingly so."

"Even so, it was one single thing which, in the end, caught Atrus's imagination; one element which made him catch his breath and make him want to go and see."

"The tree."

In the next part of the book there is a wonderful and fascinating view of Riven before the land split into five islands. Atrus is saved from drowning by two Rivenese natives, cousins of Katran, and comes in this way to meet her and become known to the natives.

Gehn has established himself as a god on Riven. He has selected certain of the natives to be in his Guild, and he's taught some of them to copy D'ni symbols, withholding certain key words without which it is impossible to Write Ages. Katran alone seems to have understood at once the true meaning of the symbols she is copying. Though not as talented as Atrus, Gehn feels she is much more docile and easier to control. He tells her that he has decided to marry her.

"Yes, Katran," he said, looking at her fondly now. "You are to be my wife. You will sit at my right hand and rule a thousand worlds with me."

He gives her thirty days before the wedding. In turn, without telling Atrus why, Katran tells him that he must fix the Age of Riven within thirty days. She has stolen blank Books from Gehn's study which Atrus will use to make his experiments so he can make the right changes to the Descriptive Book of Riven.

Katran shows Atrus the split in the Great Tree that appeared as a punishment and warning from Gehn. At least that's Gehn's story. One of the Guild spoke out of turn, questioning something that Gehn said to him. In a fury, Gehn forced the villagers to sacrifice the man, in what Katran vaguely calls feeding him to the sea. Gehn then threatened the people, telling them that if they question him again, he will destroy their world.

Katran has written an Age of her own, and she lets Atrus read the Book. He doesn't even recognize some of the symbols she's used. Gehn never taught those to him. Katran merely shrugs that off. Atrus tells her it's wonderful writing, but it won't work, which is what he thinks until she gets him to link to there. It is a marvel of imagination, something out of a dream.

While on the light side of her Age, Katran tells Atrus what Gehn has planned for her and says she would rather die than marry him. They decide to work together to save Riven from destruction. Atrus conducts his experiments, and, meanwhile, Katran tells him she's written them an Age, a place where they can go to be safe from Gehn. She's called it Myst.

He notices that Myst is very different from her other Age. It has a restraint and a deep understanding of D'ni principles that surpasses his own. Atrus realizes, now that he's seen the worlds that Katran has written, that it is possible that Gehn could create countless slave worlds, subjecting the fate of millions to his will. He sees only one solution: to trap Gehn on his Fifth Age. He intends to leave Katran safe on Myst while he does this, but she has other ideas.

(quotes from Epilogue of BOA)

"Only a remarkable woman would have done what Anna did, following us down through that labyrinth of tunnels and broken ways, into D'ni. She had known, of course, that Gehn would not keep his word. Had known what I, in my innocence, could not have guessed - that my father was not merely untrustworthy, but mad. All those years I spent on K'veer she had kept a distant eye on me, making sure I came to no harm at my father's hands, while she awaited the moment of my realization."

"Anna saw me flee K'veer and sought to find me in the tunnels once again, but Gehn had got there first. Even then she would have intervened, but for the mute. Seeing them carry me back, unconscious, to K'veer, she had known she had to act. That evening she had gone to K'veer and, risking all, had entered my father's study, meaning to confront him. But Gehn was not there. It was Catherine she met. Catherine who, after that first moment of shock and surprise, had chosen to trust and help her."

"I should have known at once that Myst was not Catherine's. But how was I to know otherwise? I had thought Anna lost. Lost forever"

"And how was I to know that, just as I made my preparations, so the two of them made theirs, pooling their talents - Anna's experience and Catherine's intuitive genius - to craft those seemingly cataclysmic events on Age Five, in such a way that after a time they would reverse themselves, making Catherine's former home, now Gehn's prison, stable once more."

"I realized the moment I fell into the fissure that the book would not be destroyed as I had planned. It continued falling into that starry expanse, of which I had only a fleeting glimpse. I have tried to speculate where it might have landed, but I must admit that such conjecture is futile. Still, questions about whose hands might one day hold my Myst book are unsettling to me. I know my apprehensions might never be allayed, and so I close, realizing that perhaps the ending has not yet been written."

These books give new depth of meaning to the games and are great stories in themselves. I highly recommend them to fans of the games. It's impossible to do them justice in this way.