I literally finished Ptolemy's Gate yesterday, so this made me sad. Happy, but still sad.

This is really amazing and beautiful! I love how you split it into three parts, each dedicated to a main character, and a fourth part to the series. Each verse gets so much of the character's essence into so few words.

This is a nice idea. But, (constructive criticism) Shakespearian sonnets are traditionally done in iambic pentameter. baBOOM baBOOM baBOOM baBOOM baBOOM.
shall I/comPARE/thee TO/ a SUMM/ er's DAY
thou ART/ more LOVE/ ly AND/ more TEMP/ erATE
(End of constructive criticism)
I love Bart!

I loved this :)

It managed to conjure up the emotions that I had when reading the books. i.e. it is a perfect embodiment of the true emotional crux of the books.

More chapters would be great!

*applaudes loudly until hands hurt*
I love, love, love the first verse. Or should I say the first two words? They so perfectly describe this hidden side of Bartimaeus. And yeah, "immortal smile" it is.
What I noticed here is how you so well portray that a part of each of them is broken. You know how we always joke about how we would hug the 3 of them because they need it, but it is nice to see their wounds out in the open for a change.
Well, I don't agree with the ending. My heart was mended only to be broken again! Naw, I'm kidding. I love this. Great job, Soul.

nice work!