A Flimsy Machine

[VaeVictis]

He had to get to the heart of the Machine (recall the human heart attached to the it, not to mention the body it was hooked up to). Plus, Mandus held out hope of finding his children until the Machine flat out told him that they were dead.

The point is that it was surprisingly easy for Mandus to find the Machine's heart. Too easy. :p

You have an interesting definition of 'easy.'
Wading through excrement, liquified bone and organs, dead bodies, being tricked into burning London, all with the dawning realization of your former self is not my definition of a good time.
Plus, it wouldn't make sense for the Machine to be labyrinthine, given that Mandus and the pigmen where the only ones operating it.