The Flash: Grant Gustin teases filming time travel scenes with cosmic treadmill, theory on Harrison Wells' endgame

Grant Gustin teased that The Flash's upcoming episodes will feature time travel, using the cosmic treadmill.

Gustin, who plays Barry Allen, recently told Movie Pilot that he is excited about the time travel scenes ahead on the show.

He said: "We have been shooting a lot that involves time travel, it gets very confusing, as far as logistics and what you are doing, and where you are, what has happened, what hasn't happened."

When asked if the cosmic treadmill will come into play, Gustin teased, "Yeah" and added, "I'm going to say that yes, Andrew Kreisberg would have said yes if you had asked him the same question."

Andrew Kreisberg earlier had revealed that the Weather Wizard would introduce an accidental time travel on the show.

He told IGN: "If you've seen the pilot and some subsequent episodes, you know that certain individuals have certain knowledge of certain events that they wouldn't have, if they didn't have access to the future."

He added, "If you're a fan of the comics, you know. The Flash is ultimately all about time travel. You'll start getting some more hints of that."

Harrison Wells' endgame and speed force

The Flash episode 12, "The Sound and the Fury", was the first time viewers saw Dr Wells as the Reverse Flash running like the speedster (without the suit). Until then, it was only in theory, as Dr Wells was mostly seen bound to a wheelchair.

At the end of episode 12, viewers saw Wells with the stolen tachyon prototype device on his chest. With the aid of artificial intelligence, he attempts to absorb the Speed Force with limited success. And he admitted that his speed is not stable as was irratic.

This confirms that Wells' speed is not inherent, like Barry's powers. Wells also stated that the tachyon device was only meant to be a temporary fix. At the end of the episode, Wells said that his "endgame" was approaching, which indicates that we are getting close to where Wells will reveal his ultimate goal.

The Sound and The Fury were introduced the first in reference to the Speed Force. Like in the DC Comics, the Speed Force is an energy field that grants all speedsters their power.

Andrew Kreisberg has admitted that Speed Force is very important to The Flash, and calls it an "amorphous thing" that serves as "a catch-all phrase that speaks to a grander universe and a grander power and ultimately grander abilities. If you know the comics and you know what having access to the Speed Force gives you the abilities to do."

Meanwhile, Hypable speculated that although Speed Force opens the show up to a lot of possibilities, one of that is the existence in the comics of the Negative Speed Force.

The Negative Speed Force eats away at the regular Speed Force and, can consume any speedster connected to it by touch. Professor Zoom, one of the Reverse Flashes of the comics, generates this force, which manifests as red electricity.

Also, in the comics, Professor Zoom infects Barry with the Negative Speed Force, hoping it would consume Barry's loved ones and other speedsters who rely on it.

If Wells is trying to absorb the Speed Force, it indicates that his character is based on the Zolomon model of the Reverse Flash, as there are several Reverse Flashes in the comics.

Moreover, Zolomon was a former friend of The Flash who sought to make him a better hero by being his greatest enemy. In The Sound and the Fury, Wells did seem to go out of its way to showcase his concern for the people in his life, specially towards Barry.

Also, Kreisberg has confirmed that Harrison Wells' endgame will happen this season.

He added, "Wells has a definitive plan, and when you look back you'll see he's had a definitive reason for doing all the things that he's done throughout the course of the season. We think it makes sense. Hopefully you all will too."

Grant Gustin has promised a shocking finale twist involving the Reverse Flash. He said, "There's a big twist that even surprised me. I've seen all the predictions online. No one has predicted the big twist that's coming at the end of this season."

With the numerous twists in the season ahead, we'll have to wait and watch how The Flash unfolds.