It looks like Game of Thrones might have revealed a huge new spoiler without anyone noticing for weeks now.

Actress Lena Headey, who plays Cersei Lannister on the hit HBO series, posted a photo on her Instagram account that may have hinted at a major development and a new character for the show. The photo depicts a heart made from stones with the caption "My stone heart" with fans speculating that Headey might be referring to Lady Stoneheart, who makes her first appearance in the epilogue of A Storm of Swords.

Cersei Lannister Becomes Devastated by Series of Traumatic Events

Lady Stoneheart, who first made an appearance in the epilogue of A Storm of Swords, was first resurrected by Catelyn Stark and leads the Brotherhood Without Banners on her quest for revenge. If she is indeed to appear during Season 4, she most likely will be seen during the season finale and might indicate a larger role for the character in future seasons.

The final episode of the season, which is titled The Children hints that the truth might be revealed for several characters along with an unexpected arrival north of the Wall that will change circumstances and definitely end with a cliffhanger that will keep fans at the end of their seats. According to the synopsis, "Dany is forced to face harsh realities. Bran learns more of his destiny. Tyrion sees the truth of his situation."

Bronn Betrays Tyrion & Breaks Their Friendship?

Meanwhile, it also looks like Game of Thrones might be globetrotting once again for another set location as sources say the series is looking to film part of Season 5 in Spain. According to Entertainment Weekly, producers are currently scouting locations in the Andalucia region and is in talks with the local film commission.

Just this last Sunday, the series tied its best ratings yet, reaching 7.2 million viewers for its first airing and 8.5 million viewers total. The highly-rated Thrones has been renewed for two more seasons, with production on Season 5 slated for this summer.