The cast roster of "Fear the Walking Dead." is starting to grow longer, and the show is gearing up to debut later this year.

Deadline reported that "Quarantine 2: Terminal" and "666 Park Avenue" actress Mercedes Mason will be joining the cast of AMC's "The Walking Dead" companion series. While there are no details yet about Mason's role, actor Ruben Blades will reportedly be in the show to portray the role of her father. 

Mason and Blades will join Cliff Curtis, Kim Dickens, Frank Dillane, Alycia Debnam Carey, as well as the recently cast Elizabeth Rodriguez in the companion series of the highly rated post-apocalyptic drama aired by AMC. 

Series producer Greg Nicotero recently talked to Melty about the core theme of the upcoming TV series, which he said focuses on the relationship between the members of a family in distress. He also said that the most glaring difference between "Fear the Walking Dead" and the original series is, the former features blood relatives who are already together to begin with, while the latter features alliances forged by circumstances.

"The spinoff really is about family," Nicotero said. "And in our [Rick Grimes] version of The Walking Dead we come upon these people, they are already sort of a rag-tag group of survivors. They've lost people on the way, but they've found each other."

He added, "So clearly that's one of the main emotional aspects, is going after your children to protect them, and getting your ex-wife and your child who's with another parent." 

As earlier reported, "Fear the Walking Dead" is set in Los Angeles, and its timeline comes before the events in the original "The Walking Dead" series. However, show creator Robert Kirkman revealed that the new series will not always stay as a prequel since it will eventually catch up and have a parallel timeline with the current "TWD." 

"Fear the Walking Dead" is expected to debut in summer, while the second season has already been ordered for 2016.