Courtesy of user "cherrick"
I've finished reading the book and I'd say it was... okay. It feels like an improvement from the previous book and also sowed seeds for future story lines. This is gonna be a very high level overview, mostly touching on the important plot points in each chapter. There will be things missing, so if you want more you'll have to read the book. Now, without further ado, here's a chapter by chapter summary.
Chapter 1: This chapter is billed as an epilogue. Cue rehash of the end of the War of the Spark novel. Assembled Planeswalkers agree to take Gideon's armor back to Theros. Guild leaders appoint Kaya, Ral, and Vraska their targets.
Chapter 2: Liliana arrives on Dominaria, despondent and borderline suicidal. Nearly drowns herself in the swamp but sees a delusion of Gideon and drags herself out and heads home.
Chapter 3: Back on Ravnica, everyone is tired and the Guild Leaders agree to let the Planeswalkers start hunting their targets in the morning. Rat is sad that Kaya and Teyo will leave.
Chapter 4: Planeswalkers decide to go to Khaladesh for a night to rest before going to Theros. Jace goes home with Vraska to bone down.
Chapter 5: Raven Man tries to tempt Lili. She engages in more self-flagellation but doesn't want to be used anymore.
Chapter 6: In Orzhova, Rat flirts with Teyo. Chief servitor Blaise, an old lady serving the Guildmaster, can't see her but really, really wants to because she's ever so kind and helpful!
Chapter 7: Tezzeret returns to his stronghold, glad to be free of Bolas to start his own machinations and prepares traps for whoever is sent to find him.
Chapter 8: Ral wants some post-war coitus. Tomik wants to study law magic to free Kaya. Ral prevails.
Chapter 9: Kaya attends to Orzhov business with the Triumvirate, basically the Orzhov Council. Rat puts on a brave face but is sad. Hekara shows up for some reason but still can't see her.
Chapter 10: Jace and Vraska make plans to visit Vryn. They resume boning down.
Chapter 11: Dovin Baan arrives on Khaladesh and immediately starts coming up with plans to leave.
Chapter 12: Rat slips out of Orzhova in the night and cries in an alley alone
Chapter 13: Chandra is dead inside and can't sleep so she goes to Dovin Baan's house. Saheeli and Huatli are there after having split with the rest of the Planeswalkers and gone to Saheeli's (shippers take note). Huatli finds some blood and tracks him a ways before losing the trail.
Chapter 14: Teyo and Kaya realize Rat ran away. Teyo goes to find her and Kaya goes to the Guildmaster summit.
Chapter 15: Planeswalkers arrive on Ravnica to pick up Jace and head to Theros. Kiora and Jaya duck out.
Chapter 16: Teysa plots.
Chapter 17: Teyo goes to Gruul lands. Rat isn't there.
Chapter 18: Planeswalkers build a cairn next to a river near Akros. Nissa RAISES A MIGHT OAK (it's in all caps in the book...). Huatli uses her Warrior Poetry. Nissa states Gideon would want to redeem Liliana.
Chapter 19: Lili berates herself some more. Uh oh, something's up at the Vess Manor!
Chapter 20: Guildmasters meet and Jaya. Vivien, and The Wanderer are there for some reason. Jaya puts up a feeble defense of Lili before accepting their judgment. She apparently followed Chandra and knows where Dovin was. The Wanderer followed Lili and knows where she is and can apparently track the damaged Planar Bridge's... emissions. Tomik reveals he knows a way to temporarily transfer the contracts from Kaya.
Chapter 21: Teyo finds Rat at the Promenade they first met at. He convinces her to come home to try to convince Kaya not to kill Liliana because they're both too pure-hearted to kill.
Chapter 22: Ral and Tomik are cute. The Wanderer has some history with Tezzeret and volunteers to guide Ral to find Tezz.
Chapter 23: Jaya brings Vivien and Vraska to Dovin's home before going back to bring Kaya to Dominaria. Vivien helps Vraska track Dovin.
Chapter 24: Tomik takes on the contracts. Kaya reveals she can use her ghost powers to take one living being with her when she planeswalks. Rat and Teyo rejoice and Team Kaya convince a tired Jaya to go to Teyo's home of Gobakhan first.
Chapter 25: Jace looks for Vraska and realizes she's keeping secrets and has his suspicions.
Chapter 26: Lili stumbles across a servant of the Vess Manor who has a collar that burns her if she defies her master. She reveals that Liliana Vess did it to her. Lili mad!
Chapter 27: Rat temporarily melds with Kaya in a passage that rivals We'mrakul awfulness of readability. Teyo meets up with his monk buddies.
Chapter 28: Lili talks to some more servants and goes home to kick some imposter butt.
Chapter 29: Ral and The Wanderer arrive on Amonkhet. The Wanderer gives some exposition about her weird inability to stop Planeswalking without willing it. Samut leads them to where they fought Tezz and The Wanderer follows the trail with Ral in tow.
Chapter 30: Vivien continues tracking Dovin. Vraska plays marbles with random girl in the street and dubs her a Princess. She receives a marble. Vivien loses the trail where he planeswalked away so Vraska goes home.
Chapter 31: Dovin goes the the last place anyone would expect! Obviously Ravnica.
Chapter 32: Teysa plots. Now with more Triumvirate!
Chapter 33: Karn returns to finding a way to fight the Phyrexians. Ajani and Teferi agree to help him plan. Ajani reveals Elspeth's backstory. Nissa returns to Zendikar. Chandra is like, way too edgy to go with her.
Chapter 34: The abbot bullies Teyo and makes fun of Jaya and Kaya's similar sounding names. A diamondstorm approaches.
Chapter 35: Lavinia is keeping secrets from Jace. Jace leaves to find someone who he's okay with mind crushing.
Chapter 36: Vraska is too clever for Dovin!
Chapter 37: Teyo sucks at Geometry again until Rat is in danger. He proceeds to single-handedly protect everyone. The abbot remembers something and tells Teyo to leave and never return.
Chapter 38: Ral prods The Wanderer to learn her history with Tezz. Then he prods her to show him her face. She reveals a golden mask. Reddit prints headline: The Wanderer is Elspeth! They track Tezz to Esper.
Chapter 40: Zoltan, a vampire and one of the Triumvirate, attempts to seduce Tomik.
Chapter 41: The abbot reveals Teyo is a natural born Shieldmage and it's the monestary's teaching that was screwing him up. He's so super proud of him, but Teyo must still leave and never return. But in a nice way. Jaya brings Team Kaya to Dominaria before peacing out.
Chapter 42: Vraska confronts Dovin who offers to help her with her Devkarin problem in exchange for keeping him alive.
Chapter 43: Jace senses Vraska's back. He meets up with Chandra and mind crushes Exava to find out the truth about the Guildmasters' plan. Chandra goes to a Giant bar to drown her sorrows.
Chapter 44: Tezzeret drops some backstory and name-drops some random Esper nemesis. A stormcloud rolls in that must obviously mean Ral is coming.
Chapter 45: Rat counts the diamonds she picked up from the diamondstorm. She flirts with Teyo some more. They arrive at Vess manor and see some servants in the garden. One of them turns around and it's Lili!
Chapter 46: Zoltan fails. Teysa plots.
Chapter 47: Vraska plays marbles with random Devkarin girl. Gasp, "someone" attempted to assassinate Jarad's son and it turns out to be none other than the leader of the Devkarin! Vraska magnanimously offers to protect him.
Chapter 48: Ral and The Wanderer fight some gargoyles. Tezz leaves the front door open. We know it's a trap but let's just walk in!
Chapter 49: Lili has been mind crushed! Attempting to remove her collar, which causes it to burn her, somehow brings her memories back.
Chapter 50: Jace confronts Vraska. They talk a bit before she leaves him to deal with guild business. Jace is contemplative.
Chapter 51: Rat infiltrates Vess Manor. A party of cabalists is being held by "Liliana". Rat can't smell the rot of her zombie guards and tries to touch one to reveal it's an illusion! Fakeiana's sapphire necklace glows and she realizes there's an intruder. Rat sees the Gem of Becoming and touches it and becomes visible! She drops it, becomes invisible again, and runs away.
Chapter 51: Lili fights Kaya. Teyo protects Lili in a shield sphere. Lili raises zombies to attack Kaya and Teyo. Rat whacks Lili with a log, knocking her out and disabling the zombies.
Chapter 52: Dovin tells Vraska that he hasn't given her the full plan, which he'll reveal step by step to keep her from killing him. He offers a plan to trick the Guildmasters into thinking he's dead utilizing Chandra.
Chapter 53: Team Kaya argue about what to do with Lili. Rat realizes she smelled djinn-smoke in the manor. Kaya agrees to put off killing Lili to save the servants. Lili agrees to die after they do her a favour.
Chapter 54: Ral and The Wanderer fight through Tezz's minions and machines. The Wanderer uses sick planeswalking tricks. Nothing personal, kid.
Chapter 55: Lili remembers how she became captured. She had allowed herself to be mind crushed rather than let the Raven Man and the Onakke use her more. Random Kor woman (Dominaria has Kor now?) revealed she knew who the Lili-mposter is and got wrecked by djinn magic. Present Lili agrees to die if they take down the fake and necrotizes her own neck to remove the collar. But wait, leave it on since it won't work if it senses it's around dead flesh? Sure!
Chapter 56: Tomik confronts Teysa after each of the Triumvirate fail to seduce/bribe/intimidate him. But this was her plan all along! She was just proving a point. She WANTS him to be the permanent acting Guildmaster so Kaya can leave whenever she wants and he agrees. Lazav appears after Tomik leaves. Just as planned. Teysa is now the puppet-master and in cahoots with the Dimir.
Chapter 57: Team Kaya execute their plan. Teyo traps the djinn and Rat destroys the sapphire.
Chapter 58: Ral fights Tezz. The Wanderer fights Boss Gargoyle. Ral unleashes a storm and accidentally knocks out The Wanderer who planeswalks away since she can't focus on staying if she's unconsious. Tezz beats Ral up but doesn't kill him and offers him his etherium arm to trick the Guildmasters into thinking he's dead so he can be free to be Bolas Lite.
Chapter 59: Rat breaks the sapphire and releases the djinn, who immediately swears vengeance upon everybody present. Oops!
Chapter 60: Tomik returns home just before Ral planeswalks in, beat to hell but apparently victorious. Tomik goes to get a healer.
Chapter 61: Rat tosses the Gem of Becoming nee Spirit Gem to Lili. Turns out it was Ugin's all along! It links Lili to Ugin who reminds her that Gideon believed in her. Now she has to believe in herself!
Chapter 62: Kaya gets punched by a djinn. Lili uses the Chain Veil to fight it. Rat and Teyo remind it that they freed it and only the fake Lili is its enemy. Lili taunts her imposter before she is burned alive. Kaya puts her out of her misery.
Chapter 63: Vraska finds Chandra and tells her Dovin is on Regatha for some reason. Chandra confronts him, fighting him to the edge of a lava stream. Vraska chops his hand off and Chandra lights him up. She sees his burnt corpse sinking into the lava. Jace finds Chandra when she's back on Ravnica and tells her Jaya had been helping the Guilds. Chandra is confused.
Chapter 64: Team Kaya argue about what to do about Lili. Cut back to Rat when she grabbed the Spirit Gem, Ugin told her that the Gem reveals the holder's true self, which is why she became visible. Ugin tells her to give it to Lili, but leaves the decision to Rat. Rat is tempted with the chance to be visible but relinquishes the Gem. Back to the present, Rat convinces everyone to give Lili a second chance. Her infectious optimism convinces Lili to give herself a second chance.
Chapter 65: Jace and Chandra find Jaya who takes them to Dominaria. She reveals that she was just protecting Chandra, but you're like, not my real mom! They find the freed servants burning Liliana's corpse. A hiliarious misunderstanding leads Jaya to believe that the servants are talking about Rat instead of Lili when they recount the story of what happened. Jace reads their minds and they are telling the truth. They search the corpse and don't find the Chain Veil but the servants tell them Team Kaya took it as proof of Lili's death. Lili would never voluntarily give it up!
Chapter 66: Ana Iora checks into an inn on Fiora. Cut back to Dominaria where Team Kaya want to take the Chain Veil as proof. After much internal conflict and mental goading by Raven Man, Lili willingly decides to give it away. That was the magic word for the Spirit Gem to poof into nothing, taking the curse of the Chain Veil with it. Rat is sad she will never be visible. Kaya tells Lili to go to Fiora and wait for them.
Chapter 67: Back on Ravnica, Teyo and Rat flirt some more before he tucks her into bed. Blaise wants to see Rat without help, darn it! Oops, Rat escaped again, but left a note this time that she's going to see her mom.
Chapter 68: Dimir assassin and vampire, Atkos Tarr, receives orders from Lazav to assassinate someone during the Guildmaster meeting set to take place the next day.
Chapter 69: Tomik meets with Kaya and explains the plan to become the de facto Guildmaster. Kaya rejoices.
Chapter 70: At the Guildmaster meeting, Kaya reports her success and hands over the Chain Veil to Niv, who locks it away. Chandra confirms she saw the body. Vraska reports that Dovin is dead and presents the hand as evidence. Lavinia uses magic to CSI that %$#%. Chandra takes the credit, but the Guildmasters just care that he's dead.
Chapter 71: A one-handed Dovin plots. He senses a change in air temperature but nobody's there.
Chapter 72: Ral raises two middle fingers and reveals that he failed to kill Tezz. The Wanderer confirms since she had returned to Tezz's stronghold offscreen and found it suspiciously abandoned. She is unable to track him and realizes that Tezz was intentionally letting himself be tracked earlier? Okay... Niv is disappointed. Chamberlain Maree is ecstatic. Tomik is pitying. Ral is sad.
Chapter 73: Chandra goes to Zendikar to see Nissa. Greg Wiesman murders the Channel Fireball ship and dances on its grave. Seriously, this section is very long and very on the nose, spelling out in no uncertain terms that its carcass is buried deep and rotting. Like, absolutely-removed-from-the-freaking-game-forever zone gone. Chandra decides she wants to become more like Gideon and is now set up for her since cancelled comic series.
Chapter 74: Jace waits impatiently for Vraska to return from the meeting. He's sure Vraska is keeping secrets and it spells choppy waters for their relationship.
Chapter 75: Vraska finds Dovin's corpse (maybe? probably?) with his other hand missing. Well, %$#%. All that plotting for nothing and now someone knows what she did.
Chapter 76: Rat returns to Orzhova and is almost run over by Blaise. She gets revenge by playing a prank of hiding a sugarbowl, but gives it back. Blaise accepts the gentle ribbing with good cheer.
Chapter 77: Blaise goes home. Oops, she was actually Lazav! Oops, Rat is actually a Dimir sleeper agent who thinks she's a vampire name Atkos Tarr! Oops, the sugarbowl was actually Dovin's hand with an illusion on it! Oops, Vraska is now in Lazav's pocket!
Chapter 78: Chamberlain Maree calls an Izzet meeting and attempts to overthrow Ral. She fails. This really came from nowhere and amounted to nothing, but I guess it shows discord in the Izzet League? Ral goes home hoping to find Tomik now that he's not needed as acting Guildmaster, but finds he's out on Guild business.
Chapter 69: Tezz arrives in a safehouse. The Wanderer appears and they begin revealing their plot. Just kidding, it was Lazav! Now that the Orzhov and Golgari are under Dimir influence - oh wait, Simic too somehow - they have set up Return to Return to Return to Ravnica nicely.
Chapter 80: Ana Iora awakens on Fiora. She has an internal debate about whether to believe in herself and wait for Team Kaya or bounce and face the consequences. She waits and joins Gatewatch 2.
Chapter 81: Jace and Vraska bone down. He again offers to go to Vryn together, but Vraska decides to stay to protect the Golgari. Jace realizes their relationship is doomed. They bone down again trying to hold onto their love. Apparently main characters aren't allowed to be in relationships. Jace goes to Vryn.
Chapter 82: Team Kaya have a bonding sesh. Kaya realizes she and Lili are more alike than they think, both relying on the innocence of the other two teammates to bring out the best in them. They decide to go to Kaya's home plane of Tolvada. This chapter is billed as a prologue, meaning there will be another book to come.
Aaaaaand we out. This book was similar to the previous, in that anytime he was writing "new" characters it read alright and when it was established characters it suffered. There was also some really schlocky passages that made me actually cringe. You can definitely feel his YA roots. Overall I don't regret reading it, but I wouldn't recommend it to anyone.