BIONICLE Legends 7: Invasion was going to be the seventh BIONICLE Legends book and was set to come out 2007. however, it was never released. It was going to be about the Toa Inika's journey through the Cord. In the story Teridax possesed Matoro's body while he used his mask.
At one point, there was going to be a battle between the Toa Inika and Vezon, where Vezon slammed Matoro's head into a wall. The Spear of Fusion would have been destroyed completely by Jaller's fire. Then a tribe of Zyglak attack the seven of them and Vezon was taken captive. It was supposed to reveal how Krana were made, among many other things, and fans were highly excited about it.
The main reason the book was never published was because Scholastic decided to shorten the book schedule of 2007 from 4 books to 3 books, so book author Greg Farshtey did not have enough space to write Invasion and tell the rest of the story in just 3 books, and thus canceled Invasion. There was a large campaign to save it on BIONICLE fan site BZPower, but it failed. Instead, the seventh Bionicle Legends book ended up as BIONICLE Legends 7: Prisoners of the Pit.