Grant Gustin has announced that production to "The Flash" has concluded.

The actor shared a picture on Instagram in which he said that he was wrapped with production of the first season. The season is only four episodes away from finishing and CW has already announced it is going ahead with a second season, especially after such a successful first season.

According to recent spoilers, fans have a lot to look forward to as the finale will feature a showdown between Barry Allen and Harrison Wells/Eobard Thawne. The episode entitled "Fast Enough" will see The Flash reunite with other superheroes to fight against Reverse Flash. Throughout the season, the characters have built to a climax that will show whether or not Barry will get justice for his mother, and save her from the man in the yellow

The new promo also shows Gorilla Grodd wreaking havoc in Central City for Episode 21, making the tension for the final episode even higher.

There are also a number of spoilers for the upcoming Episodes 19, 20 and 21. According to CW, the three episodes will be called "Who Is Harrison Wells?," "The Trap" and "Grodd Lives" respectively.

The series tells the story of Barry Allen who wakes up 9 months after he was struck by lightning. He later discovers that he obtained super speed after being hit by lightning. As a result, Barry becomes "The Flash" and fights crime in Central City.

The series has been successful throughout obtaining rave reviews and high ratings. CW and DC comics have already started to plan film version and there will be a spin-off show.

"The Flash" airs on Tuesday at 8 p.m. on the CW.