[Warning: Potential mild SPOILERS for Game of Thrones season 5 ahead.]
Unlike its fiercest competitor for the top spot in TV ratings, The Walking Dead, HBO's grim historical fantasy Game of Thrones has yet to indulge in flashbacks for storytelling purposes. Flashforwards, yes, but that's one of the perils of including a main character blessed with psychic visions.
That seems set to change in the upcoming season 5, however, which will see Charles Dance reprising his role as Tywin Lannister despite being aggressively written out towards the end of the fourth season. Combined with a casting call for 'Maggy the Frog' - a fortune teller whom Cersei and her friends visited when they were much younger - Dance's return indicates that Game of Thrones will peek into the past when it returns this spring.
Now another casting tidbit has emerged (courtesy of fan site Watchers on the Wall) in the form of an IMDb listing for young British actor Nell Williams, claiming she will play a young Cersei Lannister in three episodes of the show. The listing states three episodes will arrive in season 6, but that's almost certainly a mistake. The website's casting isn't 100% reliable, but the role is also confirmed by Williams' agency resume.
Williams is best known for her regular role on UK children's show The Revolting World of Stanley Brown, and she's not the first cast member to join the Lannister family. Dean-Charles Chapman, who plays the eponymous Stanley Brown, joined Game of Thrones in season 4 as the newly-crowned King Tommen Baratheon. Given Cersei's own life, Tommen's swift betrothal to Margaery Tyrell (Natalie Dormer) may end up having strong ties to the flashbacks in question.
If the flashback adheres to George R.R. Martin's book series, it will include young Cersei's visit to Maggy the Frog, and a prediction she finds somewhat dissatisfying. Cersei is informed that she will be Queen, but will one day lose the role to another woman - a younger, prettier woman. With a prophecy like that, don't be surprised if Cersei starts trying to slip poisoned apples into Margaery's breakfast.
In all seriousness, the casting suggests that season 5 will amp up the conflict between Cersei and Margaery. It's also possible that there will be further flashbacks for other characters, which could be an interesting way to provide backstory and provide context for the present day storylines (especially those given less time in the spotlight thus far). Then again, with so many characters and story arcs already in place, adding a series of flashbacks could serve to make the show harder to follow.
Game of Thrones returns to HBO in April 2015.
Source: Watchers on the Wall