Yes, she is writing seven books total.
The fifth book, Syren, will be published on october 5 of 2009, not in the summer. In the Spring of 2009 will be published another book in the Septimus Heap series: The Magykal Papers. You can see details of Syren and the Magykal Papers on Angie Sage's page on Wikipedia: http://en.wikipedia.org/wiki/Angie_Sage
Septimus Heap book five is called Syren and is out. It came out in October.
The sixth Septimus Heap book will be called Darke
The fifth book came out a while ago.
The seventh novel in the Septimus Heap series is Fyre by Angie Sage.
Septimus heap book six is about a darkness that invades the castle, Jenna notices it, but septimus is too busy to help. In this book, jenna becomes a witch and Septimus is starting his darke week
As of 2017, there are still no plans to do this.
Queste
The fifth Septimus Heap book came out September 29th, 2009. It is called Syren. I REALLY want to get it!
1. Septimus Heap: Magyk2. Septimus Heap: Flyte3. Septimus Heap: Physik4. Septimus Heap: Queste5. Septimus Heap: Syren6.Septimus Heap:Dark (coming summer 2011!)7.Septimus Heap:(Untitled) unknown date for coming
an adventure/magic book
"Septimus Heap Book Six: Darke" has a total of 656 pages.
The sixth book of the septimus heap series is going to be called "Darke" but isn't due to release until around April 2011. The other five books are: Magyk Flyte Physik Queste Syren and also The Magykal Papers (a companion book)