'Arrow': Oliver and Diggle Square Off in "Brothers in Arms" Preview

The CW has released a new preview for "Brothers in Arms", the upcoming seventeenth episode of Arrow's sixth season.

While the episode's promo is fairly vague, it looks like the installment will put Oliver Queen/Green Arrow (Stephen Amell) and John Diggle/Spartan (David Ramsey) at odds, particularly over who gets to permanently hold the mantle of Green Arrow.

There's no telling exactly what that will entail, but considering all of the balls that are currently in the air - the ongoing threat of Ricardo Diaz (Kirk Acevedo), the various infighting between the factions of Team Arrow, and the recent departure of Thea Queen (Willa Holland) - it will be interesting to see how things play out.

It sounds like Oliver's feud with Dig could have a major effect on the show's lead, judging by the "dark place" he will supposedly head towards in the following episode.

"This season has been very much about removing all of the support structures from Oliver," executive producer Marc Guggenheim explained during a recent interview. "One of the challenges we placed for ourselves in season 6 was we got Oliver to the end of his emotional journey in season 5. He finally moved on from the past, he was a much more emotionally complete human being."

"So the challenge for season 6 was: How — in a show that really, for the first five years, gained a lot of its story from the bad choices Oliver made — do we continue to make Oliver's life difficult, but have it come from something that he's enduring rather than the dark machinations of the soul?" Guggenheim explained. "One of the things we hit upon is the idea of we spent basically season 5 building up this team and this whole support structure, bringing him closer to Felicity again, bringing his son into his life. And in season 6 what you've basically seen, and will continue to see, is the slow degradation of all those structures."

You can check out the synopsis for "Brothers in Arms" below.

OLIVER MAKES A DARING MOVE THAT COULD COST HIM EVERYTHING — Oliver (Stephen Amell) and Diggle (David Ramsey) face their biggest challenge yet. Curtis (Echo Kellum) is disappointed to find out his new boyfriend has a firm anti-vigilante stance.

Mark Bunting directed the episode written by Sarah Tarkoff & Jeane Wong (#617).

Arrow airs Thursdays at 9/8c. "Brothers in Arms" will air on April 5th.