Emily looks everywhere but couldn't find the locket. She runs to Elena to tell her about the emergency.

"Elena, we have a problem!" (Emily)

"What is it?" (Elena)

Emily whispers "The locket's gone."

"You mean..." (Elena)

Team S wonders what their talking about. But Minwoo used his powers to overhear what they were saying.

"What locket?" (Minwoo)

"How...?" (Elena)

"I am the spirit of sound. I can also hear the tiniest whispers." (Minwoo)

"Fine. We'll tell you what we know." (Emily)

The sisters tell the boys about their past. There was a happy family of 5 consisting of a father, a mother, two sisters and a little brother. They lived happily and peacefully. That is until the original spirit attacked the town that they lived in.

"So, you know the original spirit?" (Dongwan)

"Not as well as we wanted but I did find out her motives from Eric." (Emily)

"From Eric hyung? How does he know?" (Junjin)

"Yesterday, he told me that he saw the original spirit the other day. He  also told me that she was creating spirits from humans in memory of her lover." (Emily)

"Her lover?" (Andy)

"Yes. Now back to the story." (Emily)

The original spirit captured Eric and his friend for whatever reason. After a few hours of searching for them, they saw another spirit. They couldn't see the spirit's face but saw his angel. It resembled a crown and sundals. He attacked the rest of their city until we was stopped by a mysterious person.

"That must be the spirit hunter." (Dongwan)

"You know him?" (Elena)

"He helped us on many occasions." (Junjin)

"Then you must know his abilities." (Emily)

"And we know he has an angel." (Andy)

"Yes, and he gave us a locket containing that spirits powers." (Elena)

"Why would he do that?" (Dongwan)

"We don't know. All that we do know is that the power is dangerous." (Emily)

As they were talking, Eric woke up and overheard everything. They were talking about their past and the part of the original spirit capturing him and his friend. Why did the original spirit captured him? And who was this friend they were talking about? Why would his sisters hide this from him?

As he was about to leave the infirmary, the alarm goes off. The team go to HQ and sees that Musketeer had returned.

"Not him again." (Junjin)

Eric comes in. "What's he doing now?"

"Whatever he's doing, we're going to stop it." (Andy)

"Team S, move out!" (Joon)

"Yes, sir!"

They go out to the location and see Musketeer. Minwoo, Dongwan, Junjin and Andy change into their spirit forms and summon their angels.

"Mineginah! Maestro!" "Mesiutt! Reflect!" "Meakhe! Accel!" "Mavett! Chain!"

"Ugh, you again?" (Musketeer)

"Yes and whatever you're doing, you need to stop." (Eric)

"Not until I find him!" Musketeer attacks them from behind.

"Him who? Who are you looking for?" (Minwoo)

"If you let us, we can help you." (Andy)

"Like that's ever going to happen." (Musketeer)

Back at HQ, everyone watches on to monitor Team S's moves. They looked like they were getting nothing out of him. Joon watched on to study Musketeer's special attacks and abilities. While doing that, he couldn't help but notice the Mun sisters' looks as they looked shocked.

"It can't be..." (Emily)

"Is it really him?" (Elena)

"You know him?" (Joon)

"He does look familiar but we don't know for sure." (Emily)

"Well I'm going to find out!" (Elena)

"Be careful, Elena." (Danny)

"Commander. Musketeer is causing massive earthquakes arcoss the country." (Taewoo)

"Boys, you must stop him from using his ultimate ability." (Joon)

But just as they heard the command, Musketeer was about to unleash the ability until...

"Stop! Jinkyo!" (Elena)

Musketeer/Jinkyo stopped. Team S were in shock. Elena knew the Musketeer's real name.

"Noona, how do you..." (Eric)

"No time to explain." Elena cuts Eric off and tried to go towards to a back to normal Jinkyo.

"Elena noona?" (Jinkyo)

"Yes, Jinkyo. It's me. And Emily unnie's here too. We've wanted to see you." (Elena)

"Then that means..." Jinkyo turns and see Eric. "YOU!"

"AH!" 

"ERIC!" (Elena)

"What are you doing?" (Eric)

"Where is he?" Jinkyo said scarily.

"He who? I don't know what you're talking about." (Eric)

"You know! You SHOULD know! Your friend! MY BROTHER!" (Jinkyo)

"Your... brother...?" Suddenly a light forms around Eric.

The base team looked and were shocked.

"What's happening?" (Joon)

"There's spirit energy surrounding Eric." (Hoyoung)

"But how?" (Kyesang)

Everything was too bright to see and Jinkyo retreated. As the light faded, Eric fainted. 

"Eric!" "Eric hyung!"

As the fight was going on, the spirit hunter was watching everything.

"Jinkyo... Eric..."

How does he know them? What is he hiding? Who is he?

Back at base, they put Eric in the imfirmary again. They were called to HQ so Joon can explain what happened.

"There was spirit energy around Eric." (Joon)

"WHAT?!" 

"How can this be?" (Andy)

"It can't. Unless..." (Emily)

"Unless what?" (Minwoo)

"The day the original spirit captured Eric. She must have made him into a spirit." (Emily)

"But then that would mean..." (Andy)

"The spirit hunter had sealed him." Emily started to cry and Elena comforted her. The boys couldn't believe what they heard.

"I think we could keep an eye on him." (Joon) The others agree.

"After all what happened, we need to learn more about it." (Dongwan)

"It happened when Jinkyo mentioned his brother." (Junjin)

"And also said that his brother was Eric's friend." (Minwoo)

It was a mystery all right. Eric had spirit energy and it was thanks to the original spirit. Luckily, based on the level of power he has, he was sealed by the spirit hunter. But just one thing. Why did he gave them the locket containing spirit powers when he brought Eric back to the sisters? Then, they think of something.

"Unnie, you don't think..." (Elena)

"I do think." (Emily)

"Think what?" (Dongwan)

"It's only a hypothesis but Eric's the spirit who killed our parents." (Elena)

"WHAT?!"

"He's also a spirit?" (Junjin)

"But wouldn't he remember all of that?" (Minwoo)

"That locket you mentioned. It might have Eric's powers sealed in it." (Andy)

"And the spirit hunter told us to keep it away from him." (Emily)

"We failed to keep our promise." (Elena)

"You didn't. You tried your best." (Junjin)

"And I promise you, we won't let him use his powers again." (Dongwan)

Well this is a new development. Eric was the spirit who killed their parents. His own parents. How did this happen? And who is this friend of Eric's and where is he? Could he be the spirit hunter?