'Arrow': "Fundamentals" Photos Released

The CW had released promotional photos for this week's episode of Arrow, "Fundamentals".

The episode will see Oliver Queen/Green Arrow (Stephen Amell) return to his season one costume, complete with grease paint after Team Arrow -- the "original" version which included Oliver, Felicity (Emily Bett Rickards) and Diggle (David Ramsey) -- splinter further still with Diggle leaving the team and potentially going to work for his wife, Lyla. You can check out the photos in our gallery below.

Arrow 06x18 Gallery

While there aren't many photos for the episode and they don't reveal too much about "Fundamentals" other than Oliver gets a little bit of face time with Quentin Lance (Paul Blackthorne) and otherwise appears to be alone, we do know that the episode finds Oliver in a pretty dark place as well as potentially the return of Tommy Merlyn, Oliver's best friend who died in the first season finale. Amell previously revealed that Colin Donnell, who played Tommy, would return to Arrow this season in a flashback sequence. While it's not confirmed that the flashback will take place this week, the episode's synopsis certainly sounds like it could be setting up for the return of Tommy, even if only in Oliver's memory.

You can check out the official synopsis for the episode below.

OLIVER IS VISITED BY A GHOST FROM HIS PAST — In his darkest place yet, Oliver (Stephen Amell) wonders if he has failed at everything – being a father, a mayor and a hero. His frustration rising, Oliver lashes out at Felicity (Emily Bett Rickards) and William (guest star Jack Moore).

A surprising visit from an old friend has Oliver questioning his next move.

Ben Bray directed the episode written by Speed Weed & Emilio Ortega Aldrich.

Arrow airs Thursdays at 9/8c on The CW. "Fundamentals" will air on April 12th.

Are you excited about seeing Oliver in his Season One costume? Sound off in the comments!