[chaos nods, and scans the horizon. It appears this one really is buried, since it's not immediately visible.]

We're going to have to search for it. You know your mind better than I - you should be able to find some trace of it, even if it's been hidden completely from casual view.

[How does one hide a gigantic megalith? Disguise it as something else. Much more care was taken in concealing this alteration, but it can still be found - indeed, Grievous should have little trouble spotting it, if he clearly remembers the original layout of the area they're in. His mental landscape mirrors the one he spent most of the formative parts of his life in, as many people's minds do.]