'Game Of Thrones' Season 4
Did Lena Headey revel a new "Game of Thrones" Season 4 character? HBO

Lena Headey, who plays Cersei Lannister on “Game of Thrones,” may have revealed a huge Season 4 spoiler that went unnoticed for several weeks until now.

On Instagram, Headey posted a photo that could hint at a major development and a new character in the series.

WARNING: Full “Game of Thrones” Season 4 spoilers and “A Song of Ice and Fire” discussion below. If you don’t want to know, do not read any further.

On her Instagram, Headey posted a photo of a heart made from stones with the caption “My stone heart.” Naturally, “Game of Thrones” fans were quick to comment and point out a subtle, yet clear, connection to a character that is featured prominently in George R.R. Martin’s novels but has yet to appear in the HBO series.

Headey could be coyly referencing Lady Stoneheart, who makes her first appearance in the epilogue of “A Storm of Swords.” Lady Stoneheart is the resurrected Catelyn Stark, and she now leads the Brotherhood Without Banners on a quest for revenge. Lady Stoneheart’s appearance resembles that of a zombie, considering she spent three days in a river before being brought back from the dead and she is unable to speak and features a nasty open wound across her neck and scratch marks covering her face.

Of course, Headey could be having some fun and posted a harmless photo of a heart because she knows it would rile fans up as “Game of Thrones” Season 4 covers the second half of “A Storm of Swords.” “Game of Thrones” series creators David Benioff and D.B. Weiss have already eliminated one character from Season 4, Coldhands, while adding and changing several storylines.

If “Game of Thrones” Season 4 features Lady Stoneheart, the character will appear in the season finale, “The Children.” It seems likely Coldhands did not appear in “Game of Thrones” Season 4 as the character did not add much to the story while Benioff and Weiss have been able to get Bran and his group heading toward the three-eyed raven without Coldhands as a guide. If Lady Stoneheart does make an appearance it could indicate a larger role for the character in future seasons.