I'll be doing more Bite-sized Backstory soon, but I wanted to talk a little about the new lore in Shadowkeep without having to finish out the current backstory on Mara and Uldren Sov. So, here, have this quick summary of the various Grimoire books in Shadowkeep:

First up is the book Aspect. This book jumps around a little, but it's mostly about the Vex, Praydrth, the nature of time, the Black Garden and the reassurance of its heart of Darkness, and the 227 digital copies of Ishtar Collective scientists who make contact with Praydeth and help him escape his Vex cell. I think we might also hear from Saint-14.

Some key quotes spread across the chapters:

Atelic:
The Vex understand time in a way we never will. Doesn't matter how long I spend here watching them. Doesn't matter how many jury-rigged portals Guardians fling themselves through. We live in time. They use it as a tool. Any moment that's ever happened, any moment that will ever happen, they can go back to it. Play it again till they get it right. Simulate it.

The Light's a counter to that. They come back, a Guardian comes back. They simulate an ending, a Guardian tears through it. Stalemate.

Jussive
Praedyth carves messages into the last functional pieces of his gear: anything that can serve as a bottle for his messages, thrown out on time's ocean. And what does a Guardian pay more attention to than their equipment? They'll catch someone's eye, somewhen.

He knows the wave is coming. More visions flicker past him now, burning afterimages into his eyelids. More timelines—a possibility or eventuality, he doesn't know—lost to the encroaching dark.

He knows they won't be able to handle it alone. He knows they need a warning. They need to know it's coming.

Irrealis:
Everything that has happened is, from a certain point of view, always happening. Everything that will happen is happening. If you know how to slice the ribbon of chronology thin enough, you can step through to the necessary moment. If you know how to tear it…

A hundred and sixty Mayas reach for the Chiomas by their side. A hundred and fifty-eight Chiomas reach back.

One Praedyth, waiting for the conductor's baton to drop. Uncountable Vex in the Garden, waiting for the same event, a synchrony none of them notice.

Somewhere, a veil is always lifting.

Somewhere, Kabr is always dooming himself.

Somewhere, a door is always opening.

Somewhere, they are always stepping through.

Inquisition of the Damned is about Crota’s and Oryx’s broods trying to find a new king by way of the Hive’s Sword Logic. Sword Logic basically says the strongest Hive gets to be the leader because he can kill anyone who steps out of line. Unfortunately (or maybe fortunately) for the Hive, some leaders like Crota’s daughters, have grander schemes and are beginning to question the Sword Logic.

A new, powerful Hive champion rises, a Hive brother and sister seek vengeance on the Hive leaders that led them to doom, but ultimately, it all seems to be a plan by Crota’s daughters to regain power and possibly resurrect Crota or Oryx in the same way Oryx was able to revive his two sisters after killing them.

Key quote:

The Anti-Logic:
Hashladûn peers into the Pit as the last of the congregation make their escape. Zulmak is defeated, the new champion shattered. There are none to claim the logic's prize. The Daughters' plans to return their father to glory is no longer threatened.

And, as it was before it all began, all that remains are failed sword logic and the unknown promise of nightmares.

Last Days on Kraken Mare is about the evacuation of Titan and it’s archologies as the Darkness approaches. It is a neat look at how Golden Age prosperity and idealism clashes with the impending arrival of the Darkness.

One key aspect is an elite human military unit ultimately led by Rasputin shoots down a group of scientists who tried to flee with key data vital to the coming battle. It is explained that normally Warminds cannot take human lives... but now that calculation has changed. Chilling stuff and a great little Expanse-like sci-fi story. This is my favorite book of Shadowkeep. If you only read one of them, read this one.

Key Quotes:

The Sixth Seal, Part I:
Korosec gives her his full attention, respecting her question. He is a tall, graceful, dark-eyed man with lashes so thick he seems like he's wearing permanent eyeliner. Mia remembers something from his book about cognitive empathy: show that you have made a model of their thought; show that you have listened to it. He responds, "Since I don't have any more information than you, how could I possibly be so certain?"

"Yes," Xiana says, impatiently. "That's what I asked."

He holds her gaze. Mia thinks that he may have annoyed her but also that he knows he's done nothing wrong. "The AIs who issued the evacuation order use a hammer-forged extrapolation of human morality. It is tested in trillions of simulations, under the wildest circumstances imaginable, to be sure their moral decisions agree with human values. They're not just rationality pumps. They CARE. They care the way a perfect human being with infinite compassion for all things would care. They couldn't issue an evacuation order unless it was Right. This is not a false alarm."

Kalki's Burning Sword, Part I:
And down from the sky, swift and stealthy as the Warsat that fired it, came the invisible discharge of an X-ray laser to light the shuttle's propellant like a lantern. The beam path was hot-white, straight as poured silver, collapsing instantly: a crash of pure-tone thunder as the tunnel of burnt air closes in on itself. And the shuttle opening like a ghastly blossom, the shape of a thing going upward very quickly, no longer in one piece.

"Oh, no," Mia had gasped, not understanding at first: Was it an accident? Had the phantom disaster finally arrived on Titan and struck its first blow? This was the age of life, and governments did not, ever, use force against human beings. There were always alternatives. Every soul sacred. Every evil treatable.

Then she understood what the Warmind had done.

Kalki's Burning Sword, Part II:
"I know what this means," David Korosec pronounces. He's gotten down to his knees beside Mia, but he won't reach out, won't touch her without consent. "A Warmind fired that weapon. Warminds don't take human life… unless they're in the TWILIGHT EXIGENT moral territory."

"What does that mean?" Mia demands, wanting, needing, some kind of sense.

"It means," Morgan-2 says, mercilessly, "that all human beings are assumed dead without protective action. The Warminds are now acting to maximize survival, not to minimize harm. Death is cheap, the garden's on fire, and it's a race to save whatever we can."

Letters from Eris is pretty self explanatory. It’s Eris writing reports mostly to Mara Sov, sometimes to others. The reports mostly concern to stuff we see and do in-game. Think of this book as direct background material / expanded narration for Shadowkeep itself. Good stuff if you want to get a little more out of the campaign.

Luna’s Lost contains the text form of the Ghost recordings you hear when you locate the lost Ghosts on the moon. Some of the articles contain more background info on what was happening as each Guardian met his or her end.

Revelation contains an account of the team from Aeronautics of China that found The Anomaly... remember the D1 Crucible map? Inside that strange central structure was an odd sphere that Humanity found. Clovis Bray gets involved and is the one who created the, apparently, super awesome complex shielding that mostly kept people safe. Mostly.

All the moon’s Lost Sectors are related to this story. Most notably, the K1 Communion Lost Sector with that tall central antenna... the K1 team built that without authorization and began receiving and possibly sending signals to something outside out solar system, probably the Darkness. Some of the technology the gleaned from this lead directly to the drive systems on colony ships like the Yang Liwei. The signal was also brainwashing the staff listening to it... then terrible things happen and in the final scene, Firewall, the limited AI assigned to the K1 group, prevents the few survivors from hiding from whatever is chasing them because it’s protocol does not allow it to open a door for them!

Mouse:
"Mama is on the Moon! I'm sure you'll know that by the time we listen to this, but still, it's so crazy! It was long trip, and I'm exhausted, but now that I'm here I can't sleep. Too excited, I guess.

"Anyway, they found something up here on the Moon. It's a… Well, no one really knows what it is, but it's talking to something way out there. It might be talking to another Traveler! And that's what I'm here to help figure out. They needed Mama to help them crack the code. Pretty cool, right?

"I mean, another Traveler—or maybe the origins of the Traveler—wow.

Downfall:
DAMAGE ASSESSMENT//SITE 3\BARRICADE HOLDING

"Firewall! Firewall, let us in!"

DAMAGE ASSESSMENT//SITE 3\BARRICADE HOLDING

"Firewall! There's things out here!"

"They're killing everyone!"

"Open the door, you damned machine!"

THREAT ASSESSMENT\ASSESSED//RESULT//QUOTA EXCEEDED

DAMAGE ASSESSMENT//SITE 3\BARRICADE HOLDING

"Stop!"

"Stop! They'll hear us!"

"Shh!"

"Quiet!"

SILENCE//00:02:36

"Firewall, we made a mistake."

"Yeah, we're sorry."

"Just let—what was that?

SILENCE//00:00:47

"Just, let us in."

"If you let us in the vault, we might be able to hold out—"

THREAT ASSESSMENT\ASSESSED//RESULT//QUOTA EXCEEDED

AI-COM/FRWL//NEGATIVE.

"Shh!"

"Firewall, lower your volume!"

AI-COM/FRWL//NEGATIVE. SURVIVAL IMPOSSIBLE.

"Shh!"

"Impossible? What does it mean, impossible?"

AI-COM/FRWL//NO RESCUE.

"Shh!"

AI-COM/FRWL//NO ESCAPE.

"Shh!"

"Quiet!"

AI-COM/FRWL//NO SUSTENANCE.

"Stop! Just stop!"

"Shh!"

AI-COM/FRWL//PSYCHOLOGICAL DANGERS INCLUDE, BUT ARE NOT LIMITED TO:

"They're coming."

AI-COM/FRWL//KNOWN PSYCHOSIS, RECENT PSYCHOLOGICAL TRAUMA, AND EXISTENTIAL COLLAPSE.

"They're almost here!"

"We gotta go!"

"Existential collapse? What does it mean?"

"No time! Come on!"

AI-COM/FRWL//THE END OF ALL THINGS.

SILENCE//00:00:49

[distant screaming]

Finally, there’s Unveiling which looks like it might be the story of the Light and Darkness. There’s only two chapters so far, but the second chapter seems to talk about the Light planting life and the Darkness harvesting the few results that are essential to the universe (and killing everything else?)

I’ll be watching this book closely as we get more chapters.

Key chapter (so far):

Gardener and Winnower
Once upon a time,* a gardener and a winnower lived** together in a garden.***

* It was once before a time, because time had not yet begun.
** We did not live. We existed as principles of ontological dynamics that emerged from mathematical structures, as bodiless and inevitable as the primes.
*** It was the field of possibility that prefigured existence.

They existed, because they had to exist. They had no antecedent and no constituents, and there is no instrument of causality by which they could be portioned into components and assigned to some schematic of their origin. If you followed the umbilical of history in search of some ultimate atavistic embryo that became them, you would end your journey marooned here in this garden.

In the morning, the gardener pushed seeds down into the wet loam of the garden to see what they would become.

In the evening, the winnower reaped the day's crop and separated what would flourish from what had failed.

The day was longer than all of time, and the night was swifter than a glint of light on a falling sugar crystal. Insects buzzed between the flowers, and worms slithered between the roots, feeding on what was and what might be, the first gradient in existence, the first dynamo of life. Rain fell from no sky. Voices spoke without mouth or meaning. A tree of silver wings bloomed yielded fruit shed feathers bloomed again.

In the day between the morning and the evening, the gardener and the winnower played a game of possibilities.

Note that the worms are almost 100% certainly Ahamkara, since Awoken lore from Forsaken talks a decent bit about Riven wishing to feed on Mara Sov's desires but that she is usually so sure of herself and her plans that there isn't barely anything at all between what she wanted and what might have. Essentially, she knew what she wanted and had the patience and foresight to see it slowly come to pass, preventing Riven from feeding on her even as it lived with her.

All in all, there's a bunch of good stuff in these books. I omitted some of the coolest stuff, too. Like the time the moon of Titan gets yanked along so fast by an unseen, unexplained gravity phenomenon that it literally stretches into a shape similar to an egg for a few minutes until the force mysteriously vanishes. Or the parts where some Hive are questioning the validity of the Sword Logic. Or the parts where Clovis Bray apparently hid and covered up their little war with the Vex before the Darkness ended our Golden Age. We'll cover all of this stuff... eventually... in Bite-sized Backstory. :)