James Tynion IV, the co-lead writer of "Batman and Robin Eternal" alongside "Batman's" Scott Snyder, explains to CBR News that Robin is vital to Batman lore. Comics' most iconic sidekick serves as an entry point for readers into the world of a superhero that embodies a darkness opposite from the light that shines on Superman from Earth's yellow sun. And in the weekly series, which debuts October 7, the history of Robin in the New 52 will be explored, as will the pasts of the numerous iconic characters that have worn the domino mask.

RELATED: Tony Daniel Teases "New Look" for Cassandra Cain in "Batman and Robin: Eternal"

Tynion also stated the importance that the impact Cassandra Cain -- making her modern day DCU debut in the series -- will have on Dick and the rest of the Robins when she arrives on the scene, and revealed that the mysterious backstory of Harper Row, now patrolling Gotham as Bluebird, will be a central theme of "Batman and Robin Eternal."

And while Tim Drake was Tynion's Robin when he was growing up, the original -- Dick Grayson -- is front and center in "Batman and Robin Eternal," which will be co-written by Tim Seeley, Steve Orlando, Genevieve Valentine, Ed Brisson, Jackson Lanzing and Collin Kelly and will feature covers and interior pages by lead artist Tony Daniel, as well as Francis Manapul, Scott Eaton, Sandu Florea, Paul Pelletier, Raúl Fernández and Alvaro Martinez.

CBR News: We've obviously read the solicitations for "Batman and Robin Eternal," and I spoke to Tony Daniel last week about the upcoming weekly series, but not a whole lot has been revealed yet on what the story is about. What can you share with us about that?

James Tynion IV: The biggest thing is that right now, we're in the 75th anniversary of Robin, and we wanted to celebrate that with a definitive Batman and Robin story. Bruce's legacy is very important and the way that all of the Robins past and present react to the changes in Gotham -- with Jim Gordon now running around as Batman -- is the heart of the story.

This is also a big Dick Grayson story, and this is a story that going to play out in the past and the present. There is a storyline that outlines events from when Dick Grayson was Robin. And that's a lot of fun to do and an incredible opportunity to be a part of because we haven't seen a lot of that in New 52 DCU continuity.

Robin is arguably the world's most iconic sidekick. Can you talk about the importance of role of the sidekick, in comics and fiction in general, as well as what makes Robin the consummate wingman?

Batman and Robin is one of the most enduring partnerships in comic book history. Batman, as an idea, is such a big idea. It's the idea that a person can go through an incredible trauma and come through that trauma and become something great in order to prevent that trauma from ever happening again. It's something that we can all feel and understand. But Batman is larger than life. Robin has always been the access point for readers. I think for readers around the world, the Robin they grew up with, they will always have an incredible relationship with because it's from that Robin that they grew up with Batman.

For me, that Robin is Tim Drake. The Tim Drake of the 1990s is the Robin that I grew up with. And his relationship with Batman defines my relationship as a reader and a writer with Batman. Robin is an identifier. And identifiers are powerful, powerful things. People feel very, very strongly about specific comic book characters and Robin, in particular. That's why a story like this, that brings them all together and really explores the Batman and Robin relationship, works so well. It's a strange relationship. Bruce is recruiting these children to be soldiers. There is a dark side to it. But there is also joy in that he is helping them become something better. He didn't have someone to guide him through his trauma other than Alfred. He was so determined to become this force that the Robins were able to become something different because Batman was able to take the brunt of their trauma and give them an outlet for it that he didn't have. There's something really powerful there, in a generational way.

Since "Forever Evil," Dick has been working outside of Gotham with the spy agency Spyral in the pages of his solo book, "Grayson." What can we expect from Dick when he returns to Gotham, in particular when he comes face-to-face with a new Batman?

One thing I can say about the events of "Batman and Robin Eternal" is that Dick's homecoming is definitely explored. That's a very big moment, and this story builds off of that moment in a very real way. It's the first big Bat-family story since Bruce Wayne's departure as Batman, and it really brings the whole Bat-family together. There have been other stories in the New 52 that brings a majority of the Bat-family together but this one literally has all of the Robins standing side-by-side. In a world without Bruce Wayne, we get to see Dick step into a leadership role with all of the Robins. He is the first. It's because of him that they all wear the 'R' on their chest. There is something very powerful about having him back in Gotham and interacting with the whole family.

Cassandra Cain makes her New 52 debut in this series, as well. What can we expect from Cassandra in "Batman and Robin Eternal," and what role does she play?

It's a tremendous opportunity to get to bring her back. This is something that I am so happy about. Cassandra is a character that I grew up with. Some of the first Batman stories that I read were the ones that brought her into continuity. I think "Bruce Wayne: Murderer?" is a classic crossover that nobody ever talks about. It's one of my all-time favorites.

Cassandra's tragedy is very different than the other Robins. This is someone that was designed to kill. Her tragedy isn't seeing her parents dead in an alley -- her tragedy is the moment she [first] took a person's life. There's a real powerful dichotomy there between her and Bruce and that's something that we'll be maintaining as the heart of her character. Although, there will be a big mystery about what shape all of that took here.

Cassandra is one of the main characters of this series and she is phenomenally important to the story. The story wouldn't be the same story without her. I can't say much more than that, but I will say that the first time you see Cassandra Cain in present day DCU continuity is a very special moment.

Finally, we've discussed Dick Grayson and Cassandra Cain, but there's a third major player in this series: Harper Row. She already played a significant role in "Batman Eternal" but it sounds like she's getting even more screen time here. How important is Bluebird's piece to the puzzle?

One of the big things coming out of "Batman Eternal" was the fact that Harper Row stepped up and became Bluebird. She became a part of the new generation of justice in Gotham City, inspired by Batman. As part of that story, she actually bartered with Batman that in order to protect Stephanie Brown's life, Batman would train her and make her a version of herself that she always wanted to be. But then came the events of "Endgame," and Batman is taken off the table. So she's in a unique position because she felt she was finally at that moment, she was finally at the level of a Robin, she was hoping to be a part of something -- and then she had it all taken away from her.

This story digs into Harper Row's history. Through "Batman Eternal" and "Batman," Scott [Snyder] and I have been building the mystery about her parents, as well as the mystery of why Batman has always been aware of Harper, even before Harper was aware of Batman. Those mysteries are also at the heart of this story. There is not much more that I can say about Harper other than she is absolutely one of the main characters of "Batman and Robin Eternal" alongside Dick and Cassandra. Harper never getting that final moment is important -- she never became a Robin. She became something new, but she's feels a little jaded that she never became a Robin. That's going to be a powerful thing moving forward, for her character and her place in the DCU.

"Batman and Robin Eternal" #1 strikes on October 7.