This week on "Arrow," Diggle (David Ramsey) will be forced to trust his brother Andy (guest star Eugene Bird) when an enemy from their past arrives in Star City.

According to the official synopsis (via We Got This Covered) for the episode titled "A.W.O.L.," Diggle must learn to trust Andy when an enemy of their wartime past, an agent of the criminal organization Shadowspire, pays a visit to Star City. As his brother opens up to him, Diggle learns more than he bargained for about their shared time at war. Meanwhile, Oliver (Stephen Amell) has to learn a whole new way of life.

It's interesting to note that Oliver worked for Shadowspire as seen in past flashbacks this season, so viewers will learn how the present day is connected to his time working for the organization

Recently, The CW released 13 promotional stills for the episode which shows Oliver training Laurel (Katie Cassidy). The pictures also show Andy behind bars as Amanda Waller and Diggle interrogate him.

In the promo for the episode, Waller explains that Shadowspire is a U.S. Army Special Forces unit. Oliver says that they really need to find Shadowspire, and Thea said that they need Felicity's help to do that.

But Felicity is still struggling with what happened to her and is adjusting to life in a wheelchair. Now that she is paralyzed, Felicity feels that she's not capable of being a part of the Arrow team.

"I just don't think that I'm ready to come back yet," she explains to Oliver. As she isolates herself from the others, Oliver calls her and tells her that they could really use her help. But Felicity is feeling insecure as she tries to help them using her tech knowledge.

"The last thing you need in a life or limb situation is me," she says. "I could no longer be a part of the team."

"Arrow" airs Wednesdays at 8/7c on The CW.