This week, DC Comic fans can look forward to the highly anticipated two-day crossover between "Arrow" and "The Flash," which will introduce the upcoming spin-off series "Legends of Tomorrow" and a new set of heroes.

The two-part crossover event will begin on "The Flash" on Tuesday, while the second part will air on Wednesday on "Arrow." A synopsis for the upcoming installment reveals that Team Arrow will join forces with Barry and his squad to take down an immortal villain named Vandal Savage.

"Oliver (Stephen Amell) and Barry Allen (guest star Grant Gustin) take Kendra Saunders (guest star Ciara Renée) and Carter Hall (guest star Falk Henstchel) to a remote location to keep them hidden from Vandal Savage (guest star Casper Crump) while they figure out how to defeat him. Malcolm (John Barrowman) arranges a meeting between Vandal, Green Arrow and The Flash that doesn't go as planned. Meanwhile, Felicity (Emily Bett Rickards), Thea (Willa Holland), Diggle (David Ramsey) and Laurel (Katie Cassidy) work with Team Flash to come up with a weapon powerful enough to destroy Vandal Savage," the synopsis reads, according to CarterMatt.

In Tuesday night's Episode 8 of "The Flash," which is titled "Legends of Today," Cisco's (Carlos Valdes) new girlfriend Kendra is threatened by the mysterious Vandal Savage, who possesses magical powers. He is also described in the comics as a brilliant strategist and scientist who has used his powers to bring savagery to the earth for more than 50,000 years, reports Entertainment Weekly.

To help protect Kendra, Cisco seeks help from Barry, who in turn takes Kendra to Star City to enlist help from Oliver and Team Arrow.

Their mission to keep Kendra safe becomes complicated when a man named Carter literally flies in to protect her and to provide information about why her life is in danger in the first place.

The story will then continue on Wednesday night in "Arrow" Episode 8 entitled "Legends of Today," as Team Arrow and the Flash work together to protect both Kendra and Carter, and to defeat Savage.

According to executive producer Greg Berlanti, the two-hour crossover will feel more like a movie than two separate episodes. The crossover will also uncork "probably the biggest emotional story we've ever done on Arrow," Berlanti told TVLine. He also warned that Oliver and Felicity will face a new test in their relationship.

"What's been really exciting about the show this year has been dramatizing their relationship, and how that's informed his journey and her journey," the showrunner said. "Like any relationship, there's going to be ups and downs and surprises and pitfalls, and they have some real challenges going into the break. but that's probably all I should say without getting in trouble with my cohorts!"

In addition, executive producer Wendy Mericle dropped hints about Constantine's parting gift to Oliver.

"Basically Constantine says to him that this is insurance against Reiter, and we're going to deliver on that promise entirely," the EP told EW. "It's going to help Oliver when he's in a very dark place and time when he has no other way out. It's going to be the thing that pulls him out of a very dark spot and literally saves him." However, it is not clear whether he'll be able to use it on Damien Darhk. "The mysticism that Reiter is practicing may or may not sync up with what Damien Darhk is doing."

The crossover between "The Flash" and "Arrow" kicks off Tuesday, Dec. 1 at 8 p.m. ET, and continues Wednesday, Dec. 2 at 8 p.m. ET on The CW.

Watch a preview video below.