As Gran and company progress through the abandoned mine, they encounter the Black Knight, the highest authority of the Erste Empire, who tells them that the empire is also searching for the archduke.
Katalina
This dark, heavy feeling... No. It can't be!
???
Don't lose your head, woman. You once bore the name of my empire, did you not?
Katalina
I should have known... What are you doing here, Black Knight?
Katalina
What business would one of the Seven Luminary Knights and top advisor to the Erste Empire have here?
Black Knight
That is for me to decide... along with the fate of the world. Now know your place and close that insolent mouth of yours.
Io
An imperial knight? Tell me where my master is!
Black Knight
What a plucky little brat. I presume you speak of Archduke Tzaka? I know he's not here, but little more.
Io
Don't lie to me! You guys kidnapped him, didn't you?
Black Knight
You need to learn how to address your betters, little girl. As for the archduke... I'm searching for him myself.
Black Knight
The archduke proposed this collaborative research project to the empire, but suddenly withdrew his support and disappeared.
Black Knight
I'd be careful if I were you. The archduke is trying to create something terrifying, and to do so he needs this doll... and Lyria.
???
...
Lyria
...!
A knight in black armor awaits the crew inside the empire's underground factory.
A strange aura surrounds the knight, who continues to speak.
Katalina
The archduke is targeting Lyria, you say?
Black Knight
Yes. His Excellency seemed obsessed with something when I last held an audience with him.
Black Knight
He had this truly awful look on his face. His eyes were completely bloodshot and yet strangely full of energy.
Black Knight
Primal crystal technology... The archduke was clinging to it. Lyria will be targeted just like my doll.
Rackam
More mechanical monsters just showed up, Gran! They must have come in from the entrance.
Black Knight
Speak of the devil. The archduke wastes no time...
Black Knight
You share Lyria's fate... Which means we shall meet again. May you be spared a meaningless death.
Vyrn
That knight could at least try helping us out! Let's head back to the airship for now, Gran!
Upon learning that the mechanical monsters are the archduke's creations, Io grows despondent, calling out to the archduke in an attempt to reach him.
Io
If what she was saying is true, my master must have created those machines. But why? Why would he do such a thing?
Rackam
Calm your pigtails, kiddo! You're not about to believe what some suspicious knight has to say, are you?
Io
But... I can feel it! There are traces of his magic on those machines!
Rackam
Say what?
Io
I could feel it ever so slightly last time it attacked us too. I didn't want to believe it, but...
Io
Master... why would you do such a thing? Sniff...
Vyrn
Okay, there's the exit! Once we take care of those monsters, we're home free!
Io
...!
Katalina
Io! What are you doing? Come back!
Io shakes off Rackam and recklessly chases after the mechanical monster.
Io
Master! Maaaster! You can hear me, can't you? It's me, Io!
Io
Where are you, Master?
Io
Hurry up and come home...
Lyria
Io! Stop! You're going to get hurt!
Io
Master! Let's go home! Come on!
Vyrn
Let's beat these things and get out of here, Gran! And fast!
Despite emerging victorious, Io is crushed that her voice no longer seems capable of reaching the archduke. But Lyria notices a slight change from the mechanical monster and consoles Io.
Vyrn
Everyone okay? Those guys were pretty tough!
Rackam
Is Io all right?
Io
Sniff... Sob...
Katalina
She's unharmed.
Rackam
Whew... She doesn't look hurt at least. Kids are such a pain.
Vyrn
Well, we're back to square one. Let's head into town. Sound good to you, Gran?
Io
Sob... Oh, Master... You can't even hear me anymore...
Lyria
That's not true, Io. Your voice is reaching him. I'm sure of it.
Lyria
(When Io called out to her master earlier, those machine monsters reacted to her...)
Lyria
It's okay! I'll help out if another machine monster appears! So don't cry, okay?
Io
Okay... Thanks, Lyria.
The crew takes another step toward the truth behind the archduke's disappearance, but not without some painful revelations for Io.
Lyria reassures Io who begins to feel bravery welling up within her. She's going to find her master. No matter what.
6: The Veil Is Lifted 
