Since its premiere, "Arrow" has been consistently compared to Christopher Nolan's Dark Knight" trilogy in that it shares the same dark, realistic tone. With this week's episode,titled "The Scientist," that all changes. Superpowers will henceforth be a regular staple of the "Arrow" universe.

Kicking off the episode with a super strong assailant breaking into the Applied Sciences division of Queen Consolidated, Oliver later recalls facing a similar opponent while on the island of Lian Yu. Here are all the highlights from this week's "Arrow":

Barry Allen

Right off the bat, it's clear that Barry Allen is more than just another cameo. Not only does he immediately have a thing with Felicity Smoak, but he's also completely obsessed with Starling City's vigilante. So far, all we know about Barry is that his mother was killed by a speedster when he was 11 and that his father is doing life in prison for the crime. Could Barry's mother have been killed by the time-traveling Professor Zoom?

Welcome Home, Moira

After being acquitted of all charges in last week's episode, Moira Queen returns home to a happy family and is placed back at the head of Queen Consolidated. Although it has yet to be expanded upon, it's quite evident that Moira and Isabel Rochev have a history together. Perhaps, it has something to do with Isabel being obsessed with Robert Queen, just like in the comics.

Roy And Oliver Break Up

While helping Sin locate a lost friend, Roy happens upon a corpse with bleeding eyes. When he offers to help Arrow take down the super-strong thug, Oliver reacts by shutting Roy out and shooting him in the leg with an arrow. Could this be the end of their partnership or just another bump on the road to Roy Harper becoming the vigilante's costumed sidekick?

First Aid For Slade

In the flashback portion of "The Scientist," Oliver and company discover a Japanese World War II-era submarine complete with an antidote to Slade's ailment. With his last breath, Slade apologizes to Shado for not telling her how he truly feels, with Oliver watching from a distance. If Slade has survived the injection, could this possibly be the beginning of their rivalry?

Merlyn's One Weakness

After seemingly coming back from the dead and breaking into the Queen household on more than one occasion, Malcolm Merlyn has proven to be a thorn in Moira's side. Luckily, Moira has discovered Malcolm's paralyzing fear of Ra's al Ghul and the League of Assassins. Hopefully, with Malcolm's involvement in the League, and Moira's reaching out to them, we'll be seeing an appearance from Ra's al Ghul at some point later this season!

The Flash

We all know that Barry Allen will eventually become the Flash, but how exactly will it happen? In "The Scientist," there are several nods to the Flash's comic book origins including a thunderstorm, a shelf full of unstable chemicals, and the continued mention of the S.T.A.R. Labs Particle Accelerator. Now that Barry knows the vigilante's secret identity, it's only a matter of time before he himself becomes a costumed crime-fighter. Here's hoping we get a glimpse of the Scarlet Speedster before this story arc is finished!