"Arrow" fans can look forward to another exciting episode on Wednesday as John Diggle (David Ramsey) will discover that his brother is alive and under the control of Damien Darhk (Neal McDonough).

Although Diggle was told that his brother was shot and killed by Deadshot, a preview video of the upcoming episode reveals that Andy Diggle (Eugene Byrd) faked his own death and has joined Damien's army. As a result, Oliver Queen (Stephen Amell) and Diggle will go on a mission to save Andy.

Viewers will also finally learn whether Andy was really a good guy or a wartime crime lord before he became affiliated with Damien.

According to Movie Pilot, the synopsis for the upcoming episode, "Brotherhood," reads as follows:

"Team Green Arrow's ongoing battle with Damien Darhk (Neal McDonough) is complicated by a shocking revelation. Thea's (Willa Holland) bloodlust returns and she loses control in front of Alex (guest star Parker Young)."

The director of the episode, stunt guru James Bamford, also dropped spoilers, telling TVLine the episode is "Diggle-centric."

"It dives deeper into his backstory, answering a lot of questions that have been asked since the beginning of Season 1," he said.

Bamford went on to tease that Diggle will be passionate about finding out the truth about this beloved brother, who Damien said was "dirty."

"Of course he doesn't [want to believe], but he really wants to put this to bed. He wants to have some resolution for all the feelings he's had about his brother throughout the years -- as anybody would. He doesn't want to walk around carrying this baggage for the rest of his life. He just wants to live his life. This episode has a lot to do with family -- not only Diggle's but the family unit that is Team Arrow itself, and the interactions within. It's titled 'Brotherhood' for a good reason, as that applies to not only Diggle but also his relationships, with Oliver in particular. You'll see the strength of those relationships, and the weaknesses as well. We figure one way or another, Diggle will have some answers in this episode."

Ramsey also opened about his character as he searches for the truth.

"What you're going to learn about Diggle is just how much he is committed, how much this team has become his family," Ramsey told Entertainment Weekly. "That idea is going to be repeated through each character -- through Oliver, through Felicity, through Diggle -- that this is the family."

The actor added that Diggle's quest for the truth about what really happened to his brother will help his family come closer together.

"There will be some division in terms of Diggle, because Diggle is going to get even more entrenched in this whole H.I.V.E. business and what exactly their involvement was in the death of his brother," Ramsey said. "Now, since Damien Darhk is on the scene, and he is so entrenched in H.I.V.E., it's going to be require the whole team to be closer than ever before, because Damien Darhk is a bad--s."

"Arrow" Season 4, Episode 7 will air on Wednesday, Nov. 18 at 8 p.m. ET.

Watch a preview video below.