You and Ephraim now had Duessel on your side, and he mentioned the enigmatic Dark Stone, the product of Grado's research into the dark arts. It possesses power far beyond that of the Sacred Stones. According to the rumors swirling about, Vigarde's descent into madness coincides with the creation of the Dark Stone. 

With that, your group heads to Grado by sea, only to encounter an eerie fog up ahead. 

Grado Throne Room... 

Selena approached Vigarde. 

Selena: Your Majesty... I have returned.

Vigarde: Selena... You coward. Why did you not execute Duessel?

Selena: Forgive me... It was that Valter...

Vigarde: Selena. Duessel has betrayed us. He has bent his knee to Ephraim. Are you a traitor, too?

Selena: Never! I am Your Majesty's vassal. I am yours, body and soul. Your Majesty, please, another chance, I beg you! Any order you see fit to issue, I will complete!

Vigarde: ......

Lyon: .......Selena. I have something for you. If I may, Father?

Vigarde: Yes.

Selena: What is it, Prince Lyon?

Lyon: I want you to go to Za'albul Marsh and retrieve something for me. It is a dragonstone, a very special kind of rock.

Selena: A dragonstone?

Lyon: That's right. It's very rare. There are only two in the entire world. I've heard rumors of a collector there who has one for sale. It looks like nothing but a common gemstone. I need it for my research. If I have that stone....my... Urg...gaa...

Lyon bent down in pain. 

Selena: My prince, are you all right?

Lyon: I'm fine. Don't worry about me. Now, please, find me the dragonstone. Will you approve my request, Father?

Vigarde: Yes. Do as my son asks.

Selena: Yes, understood. Your Majesty, I...would like to renew my oath of service to you here today. I pledge that I shall never again falter in my duty to you or to Grado. I beg your leave, my lord.

Selena then takes off. 

Lyon: .......

Back with your group...

Myrrh was amazed at seeing the ocean! 

(Y/N): Hey Myrrha, is this the first time you've seen the ocean? 

Myrrha: Yes, it's so blue, so vast! 

Ephraim: It is at that. You know, this is my first passage on a ship. I've never appreciated just how enormous the sea is.

You then noticed a ship coming in. 

(Y/N): Hey Ephraim, there's a ship following us, just on the edge of the fog. 

Ephraim: Is it a Grado vessel? 

(Y/N): Possibly ... but the crew ... doesn't seem to be ... oh no. 

Riev was on the other ship as he had an army of monsters ready to attacK! 

Riev:  Heh heh heh... Rise and rage, my precious children of darkness. Ruin the wood and ride the sea! Drown your foes, and devour their flesh! Come celebrate the glorious rebirth of your lord and master, the Demon King! Heh, heh, heh.

He then teleports away. 

(Y/N): THEY'RE HERE! 

The monsters begin to board the ship. 

Duessel: Is this Riev's work? We have to fight back! 

(Y/N): NO DUH WE HAVE TO! 

Everyone started to board the ship and take out the monsters, that is until another ship appeared! 

Ephraim: Another one?! 

L'Arachel and Dozla were on board. 

(Y/N): Hey, I remember those two! Come on! We have to help them! 

Ephraim: Right! 

You and Ephraim went to back up L'Arachel and Dozla, who were being attacked by a flying Gargoyle with a sword! 

(Y/N): GOT YOU! 

You used your shield to block it's attacks and then went in for the kill by chopping it's head off! 

(Y/N): That should do it! Everyone else okay? 

Party: Yes! 

Ephraim: That should do ... 

L'Arachel: And we meet once again. 

(Y/N): Long time no see. 

L'Arachel: It's strange, I recently met a young woman who resembles your friend here. 

Ephraim: You mean my sister Eirika? 

L'Arachel: Eirika? Isn't that the name of the princess of Renais? And you have a very regal air about you yourself, don't you?

Ephraim: My name is Ephraim, Prince of Renais. We're fighting to end Grado's invasion. To be honest...

You and Ephraim explained everything to L'Arachel. 

L'Arachel: Oh my! In that case, I must accompany you.

Ephraim: Do you understand that we alone are facing all the armies of Grado? We face untold numbers, and our odds of success are embarrassingly small.

L'Arachel: You clearly do not know who I am. Do not be startled by what I'm about to disclose to you... I am the princess of Rausten, theocracy of the righteous!

Ephraim: You're the princess of Rausten? Hm. You certainly don't have the bearing of a commoner, but...

L'Arachel: Ah, of course. My natural nobility gives me away every time. Truth to tell, dire circumstances have led me to begin this journey in secret. Prince Ephraim of Renais, please by assured that Rausten is your ally. Let us stand together against the villainous Grado Empire! That settles it Dozla. 
Dozla: Gwah ha ha! Understood! For you, Princess L'Arachel, I would dive headlong into a sea of evil! Why, I'd even tie myself up with ropes and chains first!

L'Arachel: Such fabulous devotion! You are truly my most loyal attendant. Let us be off then.

Now two more companions had joined!