As Arrow attempts to wrap up the story it's been telling for the past five years, tonight's episode will finally address a mystery that's been building since the pilot. All season long, Arrow has been using the threat of Prometheus to examine the choices Oliver has made over the past five years. In doing so, he's been able to question his motives, confront his demons, and move forward with a renewed sense of purpose. It's also allowed the show to look back on its own legacy and how far things have come in the time since.

Paralleling the modern day story, the flashbacks have been serving as a way to wrap up the five years that helped forge Oliver into the Hood. Through Oliver's interactions in Russia, he's grown into the hardened vigilante we first met upon his return to Star(ling) City all those years ago. And as things head towards a finale that will be packed full of familiar faces and team-ups, the show is circling back to one of Oliver's oldest friends/foes. The Arrow season 5 sizzle reel offers us a glimpse of Oliver recruiting Deathstroke to help him fight Prometheus, and in doing so the show helped set-up the potential answer for its oldest mystery.

Thanks to a CBR exclusive clip for tonight's episode, 'Honor Thy Fathers,' we now know how Deathstroke's original mask came to be on the shore of Lian Yu with an arrow through it. The shot was one of the most striking for the pilot, teasing the villain's arrival and the brutal nature of then then-new series on The CW. Since then, however, it's been unclear how the mask Slade Wilson was wearing on Amazo ended up on the island and in such a state. The new clip, however, addresses its appearance and shows Oliver turning it into the show's first Easter egg.

While the flashbacks tonight will finally move towards setting Oliver up to be 'rescued' in the original Arrow pilot, the modern day fight will pit the Green Arrow against Prometheus. Following last week's examination of Oliver and Felicity's relationship, the main action will be returning as the show heads towards a finale that's been promised to end on a huge cliffhanger.

For the past five years, we've had a general idea where the flashbacks were heading given how the show started. And considering how the modern day plots usually correspond, we were able to assume a rough trajectory for where Oliver would find himself. Just at the point where he's become his most brutal and distant in the past, the present day Oliver will look more like the comic book Green Arrow than he ever has.

There's no telling where things will go from here, however. With the flashbacks wrapped up and Oliver's confrontation with Prometheus likely coming to an end, season six is up in the air. We know Black Siren will be a recurring character, and the return of Deathstroke could also prove more permanent. No one knows how many seasons Arrow will last, but the next one may feel like a brand new show.

NEXT: John Barrowman Not Returning to Arrowverse Next Year

Arrow continues with ‘Honor Thy Fathers’ tonight, May 10th, at 8 pm on The CW.

Source: CBR