Well, I suppose the entry-point the Pater chose doesn't have to be the exact one described in that post. I was just going to have Higan blow up the entrance a bit, cause a big mess, and have his Mech struggle through a hundred meters or so of tunnel before it started to deepen and open out enough for his Mech to move around properly. Though I suppose he'll have to wait until the Pater gets there before worrying about that. I'm assuming it didn't quite make it in the previous post judging by the wording.