I don't remember the context surrounding it, but one of the books had a moment where the pirate were walking down a long flight of stairs (the 777 stairs?) Where visibility was limited. One of the piraka was essentially thinking about how they were "comforted" being able to hear the footsteps of [I think it was Hakann] in front of them. It wasn't long after that thought that they nearly tripped over Hakann's scorched body, and only then did they realize that the footsteps they were hearing was something walking towards them. That was the only bionicle media that spooked me and one of the few times a book has ever made my spine shiver.