Oliver Queen will see a few familiar faces during his stint at Slabside Supermax Prison in Arrow Season 7. According to star Stephen Amell, some villains from earlier seasons will return this year.

"Oliver is in prison with a bunch of people that he put in prison," Amell revealed at Comic-Con International in San Diego. "We were fortunate enough to get some people back on the show that you haven't seen in quite a while."

"We're investigating completely different dynamics within the mythology of the show and that is within Slabside Supermax Prison. There's a whole world, as you know, within a prison community and we'll see how long he lasts inside there and what and who he encounters while he's in there," added Season 7 premiere director James Bamford. "It's basically left open to multiple possibilities, as far as characters that could arise."

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"What I've said to the other folks is, 'What if Batman got put in prison and, for instance, the Joker was right next door?' The possibilities are endless," he continued. "I can't say exactly who or what's in there, but it's a pretty dark, horrible, evil place. We want the audience to not only feel what it's like to be confined in such a destitute place. I want the audience to feel what he feels, so you'll get -- hopefully, if we've done our job correctly -- you'll get the grit. You'll be sort of wanting to wash this prison off of you, it should feel so real."

Premiering Monday, October 15 at 8 pm ET on The CW, Arrow Season 7 stars Stephen Amell as Oliver Queen, David Ramsey as John Diggle, Emily Bett Rickards as Felicity Smoak, Rick Gonzalez as Wild Dog, Echo Kellum as Mr. Terrific, Juliana Harkavy as Black Canary and Katie Cassidy as Black Siren.