While "The Walking Dead" television series and comic book series focus heavily on Rick Grimes (Andrew Lincoln), very little has been explored regarding his family. That all changed with the release of the new spin-off graphic novel, "The Walking Dead: The Alien," which gives insight into Rick's younger brother, Jeff Grimes.

The new spin-off comic is set in Barcelona, Spain and showcases what happened to Rick's brother, who was stuck in Spain when the government began putting up quarantines during the beginning of the zombie infection. During his journey to escape and get back to the United States, he meets with a fellow survivor trying to escape, Claudia.

"I'd been fascinated by the idea of Rick Grimes's long-lost kid brother ever since he was first mentioned waaaaaay back in 'Walking Dead issue 3,' writer Brian K. Vaughan explained to the Hollywood Reporter. "It felt like the kind of fun, old-school comic crossover that never happens anymore because comics companies are owned by major corporations and there's too much red tape and hassle."

"The Walking Dead" creator Robert Kirkman explained in the report that the idea for the spin-off while they were discussing the first project for Panel Syndicate, the new publishing company that aims to distribute comic books at an inexpensive price. 

During the negotiations, Vaughan bargained that they would agree to do a hardcover for "The Private Eye" graphic novel if Kirkman allowed Vaughan to create a project in his "The Walking Dead" universe.

The ending of the graphic novel makes it impossible for Jeff Grimes to ever appear in the main comic books and in the television series but his companion, Claudia, may be able to successfully reach the United States in one piece and somehow find Rick to deliver Jeff's message. This indicates she may be introduced on the show as well. 

"The Walking Dead" graphic novel is currently dealing with the aftermath of the Whisperers while season 7 of the series will premiere this October.