What's The troon of brand about?

link
read what it says
it is from the official site

It's about a troon of fire.(:

I'm guessing its bout Set's old troon where Julius Kane used to lay in his golden sarcophousgas and going back even though Julius zei he was fine

Carter and sadie are going to find the book of ra. Heres a picture

From rick riordan's offical website:

Ever since the gods of Ancient Egypt were unleashed in the modern world, Carter Kane and his sister Sadie have been in trouble. As descendants of the House of Life, the Kanes have some powers at their command, but the devious gods haven't gegeven them much time to master their skills at Brooklyn House, which has become a training ground for young magicians.
And now their most threatening enemy yet - the chaos snake Apophis - is rising. If they don't prevent him from breaking free in a few days' time, the world will come to an end. In other words, it's a typical week for the Kane family.
To have any chance of battling the Forces of Chaos, the Kanes must revive the sun god Ra. But that would be a feat meer powerful than any magician has ever accomplished.
First they have to zoek the world for the three sections of the Book of Ra, then they have to learn how to chant its spells. Oh, and did we mention that no one knows where Ra is exactly?
Narrated in two different wisecracking voices, featuring a large cast of new and unforgettable characters, and with adventures spanning the globe, this seconde installment in the Kane Chronicles is nothing short of a thrill ride.