The much awaited crossover episodes between The CW's hit superhero series "The Flash" and "Arrow" will finally be seen in the coming days, and fans are already eagerly waiting to uncover all the details leading to the epic episodes. 

On Tuesday's "The Flash" episode titled "Flash vs. Arrow," there will be a huge matchup between the two superheroes. The Flash/ Barry Allen (Grant Gustin) and The Arrow/ Oliver Queen (Stephen Amell) need to work together to solve a murder case. 

"Barry and Oliver are kind of butting heads, but we're seeing them learn how to work together. But yeah, it's really funny because they're so different, so the conversations they have are hilarious," Gustin said. 

Amell also shared his experiences working on the crossover episodes, saying, "Episode 108 is called 'Flash Vs. Arrow,' so our titles aren't just titles. You can bet based on the title that we fight, so that whole dynamic, which took place over three nights of shooting, was a very new and different experience for me just from a technical standpoint because 'The Flash' has so many effects." 

Also, Amell said that he enjoyed working with the cast of "The Flash," especially Carlos Valdes, who plays the role of Cisco Ramos. 

Joining Amell's Oliver in his journey to Central City are Emily Bett Rickards, who portrays the role of Felicity Smoak, and David Ramsey, who plays the role of John Dingle in "Arrow." 

Meanwhile, "Arrow's" crossover episode will air a day after, and will feature the characters of "The Flash" as they visit Starling City, including Gustin's Barry, Valdes' Cisco, as well as Danielle Panabaker's character Caitlin Snow.  

Elsewhere, a promo trailer that was aired in New Zealand was leaked in the U.S., featuring the events that will take place on "The Flash's" episode this week. 

"The Flash" crossover episode airs on Dec. 2, while "Arrow" will be shown on Dec. 3.