The latest updates and spoilers for "The Flash" Season 4 reveal the new trailer for the season finale and a new DC superhero joining the "Arrowverse." The video will feature Barry Allen and Team Flash's final battle against Clifford DeVoe a.k.a. The Thinker as the latter unleashed his plan to "enlighten" the whole world in his image.

"Arrow" TV series star Stephen Amell announced during the CW Upfront presentation that Kate Kane a.k.a. Batwoman will join the "Arrowverse" as part of its next crossover event. Batwoman will represent the Batman family and it could pave the way for more DC characters in the DC TV.

The Flash vs The Thinker

The season 4 finale trailer featured Team Flash trying to save Central City and the entire world from Clifford DeVoe's Enlightenment device.

The whole city is in chaos as Barry Allen and the group tries to figure out how to beat DeVoe. Barry comes up with a solution by taking DeVoe's chair and entering his mind.

Barry fights DeVoe inside his head, while the rest of the team finds a way to stop his machine without harming both men. They received help from an unlikely ally, Marlize, The Thinker's wife.

DeVoe has dedicated his whole life trying to perfect his Enlightenment device. He has orchestrated everything that happened in season 4 including Barry's return from the Speed Force. He created new metahumans from the dark matter that radiates from it. He began capturing and absorbing the powers of the bus metahumans, including Ralph Dibny to fulfill his plans and has outsmarted Team Flash on every move.

The season finale could also tease the identity of the mysterious speedster girl who has been following Team Flash throughout the show.

She is played by Jessica Parker Kennedy and it was announced that she will be a regular cast member for the next season. The girl was theorized as Barry and Iris's daughter from the future, while Screenrant claims that she is Joe West and Cecile Hornton's unborn daughter.

Batwoman enters the Arrowverse

Stephen Amell took to the stage during CW's Upfront presentation event and revealed that next "Arrowverse" crossover will have the heroes visiting Gotham City for the first time and they are joined by Batwoman.

While Amell did not reveal the full details of the crossover, DC and comic book fans will rejoice at the fact that one of the members of the Batman family will join the cast of the "Arrowverse," proving that anything is possible. Batman has already been teased in all "Arrowverse" TV series even name-dropping Bruce Wayne's name in Oliver Queen's speech after the accusations of being Green Arrow.