Before long, Eisen was able to see some concentrations of mana in front of him. It was forming a large, hollow dome. It was a barrier that was intended to hide this group's base. That was the bare minimum they should do, really. Otherwise they would have already been wiped out long ago by the Irngrad's men.
Though, while Eisen was able to see the barrier itself, he still wasn't able to see what was obscured behind it. The magic that was used was powerful enough to obscure even the mana that was within the barrier's field from his view. That being the case, Eisen wasn't directly sure how they were going to get in here. There didn't seem to be anything physical that could be triggered from out here. So instead maybe there was something like a passphrase? Or someone was inside that could create an entrance for whoever might be approaching, if they were supposed to come inside.