The Keep of Ages: Book Three of the Vault of Dreamers Trilogy

Name: The Keep of Ages: Book Three of the Vault of Dreamers Trilogy
Price: 11.99 USD
Availability: InStock
Rating: 4.6 (90 reviews)
Author: O'Brien, Caragh M.

by O'Brien, Caragh M.

Science Fiction Young Adult

4.6 (90)

4.6 stars from 90 reviews

400 pages~6.7 hr readPublished by Roaring Brook Press

$11.99At peak price

Last checked: May 12, 2026

Hidden GemHighly rated but flying under the radar. Fewer readers have found this one yet.

Price history: $1.99 – $11.99

Full price — consider adding to your watchlist for a better deal.

Price range: $1.99 – $11.99

Buy on Amazon - $11.99

0 readers are tracking this book's price

Fans of these authors will like this...

Veronica Roth
Leigh Bardugo
Becky Albertalli

Fans of these books will like this...

Illuminae
Six of Crows
The Hunger Games

Perfect for you if...

You've read the first two Vault of Dreamers books and need to know how Rosie's fight against dream mining ends.
You enjoy speculative sci-fi that asks unsettling questions about consciousness, reality, and what makes us human.
You like high-stakes finales where the protagonist has to outsmart an antagonist who knows their fears intimately.

Maybe not for you if...

You're starting this trilogy fresh. This is book three, and you'll be lost without the setup from books one and two.
You prefer lighter reads or stories where reality stays straightforward and grounded.
You want a slow-burn mystery. This one is propulsive and moves fast, leaving little room to pause.

About this book

In the final book of the Vault of Dreamers trilogy, Rosie Sinclair travels across the country after Dean Berg kidnaps her family. Her search leads her to Grisly Valley, a contaminated horror theme park in ruins, where she suspects Berg may be manipulating her to induce fear for another dream mining procedure. As Rosie works to outmaneuver Berg, she discovers an ultimate vault of dreamers and encounters a consciousness more powerful and dangerous than anything she has faced before. Confronted with both unspeakable suffering and otherworldly beauty, Rosie must learn to trust her mind, her friends, and reality itself to shut down dream mining once and for all. The conclusion explores what it means to be alive through speculative storytelling.

Get the best deal every time

We track price drops, sale patterns, and predict when this book will go on offer next.

Price History

Kindle price over time. Green zones = periods when the book was free.

$1.99 – $11.99

Price has dropped 16 times over the last 2 years. Goes on sale roughly every 43 days. Typically stays discounted for 67 days.

Sales Rank

Amazon sales rank: lower number = better selling book. #1 is the bestseller.

Currently around #371K in the Kindle store — a niche title.

Rating & Reviews

Purple line = star rating over time. Blue area = total review count growth.

Currently 4.6★ from 90 reviews

Review activity has been quiet recently. Rating has remained stable at 4.6 over the tracking period.

Sale Prediction

Actual Predicted

Based on past patterns, a price drop could happen soon. It typically goes on sale every 43 days and the last drop was 92 days ago. Typical discount: 83% off.

Prices shown in USD from Amazon US. We continuously pull new data to improve tracking. If dates look old, it usually means there has been no significant change since the last data point.