[This is a review for Arrow season 2, episode 16. There will be SPOILERS.]

With the introduction of the Suicide Squad, Arrow welcomes back a discussion of the fairly tricky moral gray area that Oliver, and the series as a whole, has been splashing around in since the illustrious Mr. Queen snapped a would-be kidnapper’s neck in the series premiere. Rather than simply sift through the issue of whether or not the Arrow should be killing those he comes up against, the episode takes a look at the kinds of vigilante activities Oliver, Diggle, Sara, and Felicity get up to on a regular basis and place them in a much larger, global arena, thanks to Amanda Waller (Cynthia Addai-Robinson) and her crew of forcibly obedient convicts.

Suicide Squad‘ is not just another welcome Diggle-centric episode that affords David Ramsey his own flashback sequence from John’s time in the military (complete with an appearance by Farscape‘s Ben Browder), it also helps to expand the Arrow universe in dramatic fashion with, among other things, the unmistakable vocal stylings of one Harley Quinn. While Quinn doesn’t factor into the actual mission Waller has tasked her team of dead men walking with, the implications of her presence wind up being one of the show’s more significant nods at the world beyond Starling City in quite some time. And with Oliver well past the point of worry over Slade Wilson’s sudden reemergence and his vow to exact revenge for Shado’s death on Oliver and his family, the aptly titled ‘Suicide Squad’ is the perfect time (for the purposes of the story, anyway) for Diggle to step away from Team Arrow, even if it means he’s halfway around the world when the most deadly assassin in the world is passively aggressively taunting Starling City’s resident Emerald Archer.

But sometimes, these things can’t be helped. Amanda Waller’s influence is impressive after all, and besides, with Diggle getting more than friendly with his ex-wife Lyla (Audrey Marie Anderson) in the Ostrander Suite, any idea that he’s not already committed to seeing Waller’s reckless plan to stop a deadly nerve agent through to the end is as unlikely as Oliver suddenly hanging up his bow. Just because he’s taking point on the mission doesn’t mean Diggle can’t have serious moral reservations about Waller’s methods, however.

By juxtaposing the acceptable level of risk those tasked with doing “the right thing” are willing to put people other than themselves in, ‘Suicide Squad’ runs a nice parallel between Diggle’s misadventures with Deadshot, Shrapnel (briefly), and Bronze Tiger, and Oliver’s realization that pushing Sara away isn’t going to keep her safe from Slade. It’s a complex decision that, from Waller’s perspective is only one step removed from personally killing the members of her own team – as she apparently does when Shrapnel attempts to go AWOL mid-mission. Meanwhile, Oliver’s decision to let Sara in carries with it a similar level of danger, but it’s one that is reached far less reflexively, and with his partner’s consent.

In the end, ‘Suicide Squad’ finds Oliver turning to Waller for help locating Slade, while Diggle not only finds himself back together with Lyla, but also questioning his need for vengeance against the man who killed his brother. It’s a step forward in both character’s development that demonstrates the kind of man Diggle is, and just how serious of a threat Oliver perceives Slade/Deathstroke to be.

Arrow continues next Wednesday with ‘Birds of Prey’ @8pm on The CW. Check out a preview below: