Tonight sees the season premiere of Arrow, last year's most exciting new show. We caught up with stars Stephen Amell and David Ramsey, plus Malcolm Merlyn actor John Barrowman back at Comic-Con, and they explained to us how Oliver's failure at the end of season one will affect what happens in season two.

Spoilers ahead...

Oliver's Failure

At the end of season one, Oliver fails pretty badly. A big chunk of StarlingCity is destroyed, his friend Tommy dies, and his mom goes to prison. As season two begins, the shadow of these failures hangs over Oliver, Amell tells io9 β€” especially the death of Tommy.

So does this mean that Oliver will be more careful about hiding his secret identity than he was in the first season? Amell responds: "I hope he's learned his lesson. Revealing himself to Tommy ended up being Tommy's death-knell. I'm sure he would rather, in retrospect, have sacrificed Tommy's father than sacrifice Tommy."

So who's holding everything together now that Queen Consolidated and the Queen family are falling apart? Ramsey says that Diggle will continue to be the calm voice at the center of everything, the person that Oliver can (almost) always lean on. "He's always the rock."

And Amell says that Oliver's sister Thea is "doing well. Thea is doing the best out of everybody right now, in season two, in terms of where she is and how she's doing." And meanwhile, Amell says "Oliver's going to try" to hold everything together.

"The first season of Arrow was kind of like Batman Begins, with the formation of a kind of hero-vigilante," says Ramsey. "I think season two is the legitimate formation of a hero. Diggle has a big part in that formation."

And given that whenever Oliver and Diggle disagree, Diggle is usually right, maybe some of Oliver's hero's journey can involve recognizing that he should listen to Diggle more often? Ramsey says this could definitely happen.

Diggle is "kind of Yoda" to Oliver's Luke Skywalker, and "he has been wrong a few times," but he's generally right, says Ramsey. "He's a badass Alfred," Ramsey says of Diggle. "And I think Alfred's kind of always right. Like, 'No, Bruce, No Bruce.'"

A More Crowded Arrowcave?

With more characters joining the cast, and more people possibly learning Oliver's secret, are we going to see a more crowded Arrowcave than just the core group of Oliver, Diggle and Felicity Smoak? Amell says the Arrowcave is "getting an upgrade, but it's not necessarily getting more crowded."

"You like Team Arrow, right?" Ramsey says. "So do we." All he'll say is that "I'm not at liberty to say, exactly, but we've heard that sentiment, and they're listening."

One new character who's getting introduced this season is the Black Canary, played by Caity Lotz. How will this dynamic be different than it was with the Huntress in season one? "Helena was just wild and crazy. Batβ€”-crazy," says Ramsey. "Will Black Canary be bad and crazy? I don't know, but she will be a badass."

At least this means that there'll be more tough women in Oliver's life. How will Oliver deal with that? "Dynamic women in Oliver's life don't always work out very well," cautions Amell. "But maybe this will be different."

Speaking of characters who know Oliver's secret, we know that John Barrowman will reappear this season β€” but it might just be for flashbacks, Barrowman cautions. We asked Barrowman if it's really possible that such a master strategist as Malcolm Merlyn could have been killed off so easily, and he laughs. "He had a backup plan to blow up the city," says Barrowman. "Maybe he had a backup heart stashed somewhere as well."

Diggle's Fisticuffs

There will be "a lot more to do with Deadshot," Ramsey says. "We have a very interesting storyline with Deadshot... There will be some of that comeuppance for him."

And Ramsey says he's really excited to explore Diggle's backstory. "We'll see his connection to ARGUS," and how ARGUS connects with his past. He's excited to see more of Diggle's history in the military, and just build up his past in general.

Will Diggle make a move on his brother's widow this season? "Been there, done that," Ramsey says, but then he adds that we will see some of that this season, and "we will make a choice" about that.

Ramsey promises Diggle will get to step out on his own and take part in more action in season two. "I love Diggle in action. I love Diggle in the fisticuffs."