[Zope-dev] The object hierarchy

I've been fiddling with zope for about a week now, and I'm just trying to figure out this little hole in the object hierarchy so that I can get relly working on my project. I'm not entirely sure what vocabulary to use yet, so please bear with me. I'm trying to navigate around the object hieararchy, and I can find a single object's subobjects by using hasattr and so on, but what if I want to navigate to a different position in the hieararchy? As far as I can tell, objects don't have a pointer to their parent, so I've got a couple of options - find the root (which is preferable), or stuff an arbitrary root into a global variable for later use. Ideally, I'd like the former course.