Of all the questions one might have expected a fan to ask Stephen Amell at a convention appearance, the screamed phrase 'What’s in the box?!?' is, let’s be honest, pretty far down the list of possibilities. And yet, that’s exactly what happened at MCM London on Friday afternoon — and, perhaps even more surprisingly, Amell knew exactly what the question was actually about.

After checking that the fan asking the question was not his former Arrow co-star David Ramsey — to be fair, the light was not in Amell’s favor, but the questioner was actually someone who identified themselves as Sam — the actor explained, “Me and David Ramsey, we’d always had an inside joke, one year it was the Bane voice.”

Amell then proceeded to do a pretty spectacular version of Tom Hardy’s Bane voice, suggesting that he missed his calling as an exceptionally niche impressionist. As it turned out, that wasn’t the only think they’d get up to — nor the only movie the in-jokes would reference. “We’d do ‘what’s in the box’ [from Seven],” he continued, “just yell ‘What’s in the box?’”

The in jokes were, he explained, the “only way to make that show” — meaning Arrow, something that he couldn’t name due to the ongoing actor’s strike. Because each script was somewhere in the region of 52 pages, with at least one action sequence that would take a long time to shoot, that meant more intimate scenes, often featuring Amell and Ramsey in the Arrowcave, would be filmed in marathon sessions to try and maintain an 8-day shoot for each episode. On those days, they’d find ways to entertain themselves to maintain their sanity. Hence, “what’s in the box?”

Of course, that wasn’t answering the actual question that was asked. Thankfully, Amell was prepared to do that, too.

“What’s in the box? Susanna! Susanna was in the box,” he said, with a grin. For those unfamiliar with Arrow, Susanna is Susanna Thompson, who played Oliver Queen’s mother Moira, murdered by Slade to protect her son’s secret. It’s not exactly the way that Seven played out, but it’s close enough.

If this doesn’t make you want to revisit the Arrowverse, I’m not sure what will; here’s a guide to the best way to do that.