A storytelling game of spirit nukes and blood god wrestling smackdowns.
I'm going to talk about the Week of Nightmares first, because that's the part of Time of Thin Blood that everyone remembers. The Ravnos Antediluvian awakens from its slumber, lured by the spilled blood of Methuselahs who were themselves awakened from the deaths of lesser vampires, and goes on a rampage. Three 鬼人 bodhisattvas travel to India to fight it, the psychic backlash from a being with Auspex 10 and Chimerstry 10 causes dreams and nightmares to become reality all over the world, and eventually the Technocracy declares Code Ragnarok and nukes the battle site from orbit. As it dies, the Antediluvian pushes all its rage and hunger into his descendants, causing all Ravnos in the world to go into cannibalistic frenzies, and when it fades three days later less than ten percent of them are still alive.
It's pretty silly. Sure, we all know, deep in our heart of hearts, that shadow tentacles throwing cars and power metal playing over montages of sunglasses-wearing vampires killing each other is why we like Vampire: the Masquerade, but there is an unspoken line beyond which things just become too ridiculous and the Week of Nightmares crosses it. At least, the version of it in this book does, because the reader gets the full scope of the events and without the mystery it comes across as, well, blood god wrestling smackdowns. I'm not sure it's even possible to say "spirit nuke" in a serious conversation.
I do have positive feelings toward the Week of Nightmares, though, because I ran a game in university where one of the PCs was a Ravnos, so I used it there. Her powers went out of control, she had weird dreams of a tiger, a dragon, and a crane fighting a demon, and eventually she went into frenzy, all against the background of the Sabbat invasion of Philadelphia. The players didn't know that there was anything sinister going on, other than the one offhand reference I made to seeing a typhoon in Bangladesh on the evening news, and you can bet I never used the phrase "spirit nukes." These kind of world-changing events can provide great material for STs to use on the ground while keeping the mystery intact. They can also be pointless and stupid. Sure, the Ravnos as a clan are shockingly offensive if you think about them for even a moment--Roma vampires who literally need to steal (or kill, or do drugs, or whatever) and have that hoary folklore-derived powerset of D&D illusions--but I bet Ravnos players weren't happy with the STs who killed off their characters after this book came out.
Now on to the actual topic. Time of Thin Blood is about the highest generations of vampires where the Curse of Caine runs weak. Around half of 14th-Generation vampires don't have strong enough blood to Embrace, but half do, and then the 15th Generation is the final limit. Except, not entirely, because the curse is so weak that not all biological processes are stopped by becoming a vampire, and some 15th-Generation vampires can even have children.
That theme of stasis is what the book keeps coming back to. Vampirism holds its victims unchanging through the ages, both physically and, in some ways, mentally and spiritually. But this doesn't happen to the youngest Cainites. Not only can they sometimes have children, they can create new Disciplines with casual ease, something even the most powerful Methuselahs find nearly impossible. Their very existence is shaking up the Jyhad as some of them have the power of prophecy. Centuries-long schemes can be unraveled by a seer showing up and blurting out something that they don't realize should be kept secret.
All of this provides a great take on a usual vampire game. It's a good entry point for people who don't know the setting, because most thin-blooded don't get any kind of education into vampire politics and only know what an ordinary person knows plus, "Now I need to drink blood and can't go out during the day." It's the classic outsider introduction technique and it can work really well as a way to bring people into the setting, as long as the ST doesn't go overboard on shoving the lack of power the thin-blooded possess in their faces.
Next to the Week of Nightmares, the beginning of the book is the most memorable part. It's done up as an in-world scientific report by one Dr. Netchurch investigating the powers and weaknesses of the thin-blooded, and ends up documenting several thin-bloods who made their own Disciplines, anomalous instances of beard or nail growth following extreme blood expenditure such as after healing wounds or physical exertion, visions of import to his own history, the possibility of dhampir births, and finally empirically proves the existence of the blood point--or "Vitae Efficiency Unit," as the good doctor dubs it. This was the most interesting to reread, because I remembered the Week of Nightmares but I didn't remember this report, and Dr. Netchurch the Only Sane Malkavian is one of my favorite canon characters.
And I guess that's the only major problem with Time of Thin Blood. It's a really good book about how to play characters with one foot in vampire society and one foot outside, sometimes with one foot in their mortal lives, and how to deal with the changes that the existence of vampires who can have children and see the secrets of their elders with casual ease brings to the Kindred. But whenever anyone talks about the book, blood god wrestling smackdowns is what gets brought up, and it's a shame to reduce it to that. There's a lot that's good here for even the most personal-horror-focused game