Season 1’s Arrow is not the Arrow we’ve grown to love as we begin Season 4. This year features magic (Damien Darhk), zombies (which, technically, Thea and probably a returning Sara both are), and a very comic book-like version of Diggle, which has already sparked reams of Internet controversy. And yet, none of it feels wrong; the grounded tone of the show has been consistent from the beginning, and that’s the reason it’s become the cornerstone of a growing empire.

We spoke to David Ramsey, the show’s voice of reason in the form of John Diggle. Without him, Oliver Queen wouldn’t still have a mission. Without his genuine response to Barry Allen’s superspeed (“Man, that’s not freaking you out?!”) last season, The Flash lacks believability. In fact, Ramsey is very much looking forward to the upcoming Legends of Tomorrow spinoff. “Remember Diggle’s reaction to the Flash?” says Ramsey. “I can’t wait to see his reaction to Hawkgirl!”

Related: ‘Arrow’ Season 4: What We Know So Far

Mending the broken relationship between Diggle and Oliver also plays a big part this season. While working undercover within the League of Shadows last year, Digg’s wife and child were kidnapped, and he has yet to forgive Oliver. On top of that, he’s been running a well-oiled machine in Oliver’s absence. “Diggle is an Army guy, Special Forces. He’s all about the unit.” The Arrow (newly christened Green Arrow this season) has always been a lone wolf, so there are multiple levels of friction, but Ramsey says the bad blood won’t last forever. “Oliver, this season, learns to respect [his leadership skills], and that’s one of the things that brings them together.”

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Diggle also is integral to the H.I.V.E. story, which is what brings big bad Damien Darhk (Neal McDonough) to Starling City (newly rechristened Star City this season). “Diggle has a personal reason this season to be more involved and more active in the field,” since it was H.I.V.E. that hired Deadshot to kill his brother, Andy.

Related: ‘The Flash’ Season 2: What We Know So Far

Executive producer Wendy Mericle told press at an Arrow screening that Diggle’s search to find out why his brother was killed will “take him to a dark place.” He’ll be keeping secrets from the team and, essentially, doing “all the things he once condemned Oliver for. How’s that going to reverberate?” The writers are excited to explore what happens when Diggle is no longer the moral compass Oliver can refer to.

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