A Brooch and a Breach

Use the Spear of Truth to pierce the illusory wall on the Isle of Perils. Take care of the guards and use the brooch to summon Klavdia and report your success to her.

OK, let's play ghost busters at a later time. Now, let's see how good this spear is in the real world. Remember the flickering wall that prevented us from exploring the ruins? I think this spear will be of greater help than a hundred-ton battering ram.
Go to the wall and try piercing it with the spear. I reckon there should be no problem this time. Take my brooch. If you manage to make a breach in the wall, rub the stone. I'll teleport to you and we'll decide what to do next.

I wonder if we draw too much attention to us by using this artifact from the illusory world...

Did it work? That's what I thought. Excellent! And now... You like sticking your nose where it doesn't belong? I, for one, live for it. So that's what we're gonna do.