Oliver will prepare to battle Slade and Diggle will return to help the team in a new case, in episode 17 of season 2 of Arrow.

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In the next episode, The Promise, Slade is back in Starling city and he is out to get Oliver's blood. And after the release of the synopsis of episode 17, Suicide Squad, it seems like the Slade Oliver feud will be dragged on for a while. Oliver will have to prepare to combat his former friend who has sworn to destroy Oliver and his family.

The synopsis also reveals that Diggle will be helping Amanda and A.R.G.U.S. to take on a warlord from Afghanistan, but he will end up finding himself in a sticky situation.

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Here's the official synopsis:

"Following Slade's (Manu Bennett) return and his promise to make good on his threat to destroy Oliver's (Stephen Amell) loved ones, Oliver focuses all his energy on preparing for battle with his former friend. Sarah (Caity Lotz) tries to help but, fearing for her safety, Oliver pushes her away. Meanwhile, Diggle (David Ramsey) is recruited by Amanda Waller (guest star Cynthia Addai-Robinson) and A.R.G.U.S. to stop a warlord (guest star Lee Majdoub) he knew from his time in Afghanistan. Always the soldier, Diggle agrees to help. However, he's not prepared when Amanda introduces him to the rest of the team -- Deadshot (guest star Michael Rowe), Bronze Tiger (guest star Michael Jai White) and Shrapnel (guest star Sen Maher), all criminals he and Arrow helped put away. Lyle (guest star Audrey Marie Anderson) defends the team and explains the world is a complicated place, but Diggle isn't sure he agrees. When the mission takes a dangerous turn, Diggle is forced to make a difficult decision."

Suicide Squad will air on March 19 at 8 p.m. on the CW.

Watch a promo for episode 15:

Tags: Arrow Season 2