'Arrow' Season 2, Episode 15 Spoilers: Watch Deathstroke vs Oliver Queen, Black Canary Trains Roy Harper [VIDEO]

"Arrow" Season 2, Episode 15, "The Promise" spoilers reveal Deathstroke, aka Slade Wilson (Manu Bennett) is ready to confront Oliver Queen (Stephen Amell). To help The Arrow, Black Canary (Caity Lotz) preps Roy Harper (Colton Haynes) for a big fight. The CW has officially announced a third season for Arrow. This new episode is expected to justify such a move (not that it still has to be justified at this point).

Spoiler alert: This feature contains more spoilers on Arrow 2x15, titled "The Promise." This episode airs March 5 on The CW. Read at your own risk.

"Five years ago, I made you a promise. Now I'm here to fulfil it," Slade Wilson's voice hints an action-packed episode this week on The CW's Arrow. This promise means vengeance. Deathstroke is out to get his revenge against Oliver Queen. All this for the death of Shado (Celina Jade) on the island.

"His name is Slade Wilson," Black Canary says. "Unless we stop him, he's gonna kill Oliver." It is believed Sara Lance is speaking to Roy Harper here. Scroll down to watch the promo video for Arrow Season 2, Episode 15. It will be Mirakuru vs Mirakuru once Roy Harper confronts Deathstroke. Fans can assume Roy will survive the encounter. But will Sara survive, as well? As much as many fans have already loved Sara Lance as The Canary, Caity is really just playing the "beginning of the story of the Black Canary." Then again, it looks like Slade will be in Starling City until the season finale.

READ: 'Arrow' Season 2, Episode 14 Spoilers: Oliver Queen Fights Another Big Villain, Watch Black Canary Work the Salmon Ladder [VIDEOS]

It's present day Oliver Queen versus present day Slade Wilson, now known as Deathstroke. They saved each other's life on the island, and Shado loved them both dearly. But now Slade is the big bad villain that The Arrow has to kill. This massive conflict in Arrow Season 2, Episode 15 is probably the reason why Stephen Amell has been promoting this episode on Facebook and Twitter. This is a must-watch episode.

Naturally, avid viewers of the show will find out more about what happened to Sara Lance, Slade Wilson, and Oliver Queen on the island. Cast and production interviews confirm the island tales will go on up to Arrow Season 3 -- and the season(s) after that it the show keeps doing well in TV ratings.

"No chances. No mistakes." The Black Canary is in costume. And she seems to be talking to Roy Harper. This new Arrow episode is expected to be spectacular in terms of remarkable quotes and grand comic book-inspired stunts. Many fans agree that Arrow Season 2 is surpassing its freshman year.

Watch: Arrow Season 2, Episode 15 ('The Promise') Promo Video (The CW on YouTube)

As a bonus, rumour has it that Felicity Smoak (Emily Bett Rickards) may be explored further in Arrow Season 2, Episode 15. It makes sense to dig deep into her past. After all, she is one of the most interesting characters on the Arrow TV adaptation. Yet she had a relatively smaller and very different role in the DC Comics universe.

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