Arrow Non-Spoiler Review: "Haunted" Is The Most Important Episode of the Season

Even if you take away the fun and the potential long-term implications of John Constantine making his way from a cancelled NBC show onto The CW's Arrow this week, Wednesday's "Haunted" is the most significant episode of the season so far.

As we saw on last week's episode of The Flash, titled "The Fury of Firestorm," The CW is in full-speed franchise building mode, moving everything inexorably closer to DC's Legends of Tomorrow, which is expected to debut in January. With Sara Lance's story on the boards in a big way for "Haunted," it was clear this would be an important episode, but some fans had wondered whether a guest appearance by a former DC Entertainment leading man would be a distraction from the main plot, and whether Constantine would take over the episode.

He doesn't -- which will of course strike different members of the audience in different ways. Many Constantine viewers had hoped this week's Arrow would be essentially Constantine Episode Fourteen, revolving around Matt Ryan's take on everyone's favorite petty dabbler in the dark arts. The hope among some -- seen most visibly on Twitter and Tumblr -- is that a highly-rated Arrow guest appearance could lead to bigger things for Constantine, either at The CW or someplace like Netflix or el Rey (where re-runs of Constantine currently air).

That said, it's likely best that Constantine doesn't overtake the episode. Not because Matt Ryan isn't great in the role -- he takes it up here with ease and is so good that ever scene he's in is a painful reminder that this could be the last time -- but because he's brought into the episode in service of the Arrow storyline. While the role John Constantine plays in the story could have been fulfilled by any number of DC Comics magic users, there's no question that as guest appearances go, this one was well used. The decision to tie a clamored-for crossover to tie up a prickly loose end in the ongoing story is a clever one.

This is, ultimately, an Arrow storyline, ably assisted by the charming, roguish John Constantine.

We also get big moments for Echo Kellum's Curtis Holt, Caity Lotz's Sara Lance (obviously), and stellar perforamances by Katie Cassidy and Paul Blackthorne informing the A plot while a subplot with Emily Bett Rickards's Felicity and Brandon Routh's Ray Palmer simmers in the background, heating up throughout the episode and promising big things for the future.

It could be argued that Constantine's appearance isn't even the biggest thing in this episode, which speaks to the way the Arrow and The Flash creators like to do things. Barry Allen got struck by lightning, and while we all knew it was coming, seeing him make Oliver Queen's first mask was an unexpected treat. The big battle between The Flash and Reverse Flash carried with it an unexpected guest appearance by Arrow and Firestorm. This is their M.O.: When you're really excited about some specific thing that's going to make you geek out, they give you more things to geek out about, so that you can stay excited even after that initial moment fades. It's effective storytelling, and it's used perhaps better this week than ever before.

Arrow airs on Wednesday nights at 8 p.m. ET/PT on The CW. This week's episode, "Haunted," features a guest appearance by Constantine star Matt Ryan as John Constantine.