The Game of Thrones whodunit might be over before the Purple Wedding has even had 24 hours to marinate on the Internet.

Patricia Hernandez of Kotaku.com has put together a pretty foolproof theory and suggests the filmmakers told us who the murderer was before it even took place.

CLICK HERE to visit Kotaku to read Hernandez's theory, complete with photos and GIFs. You may be ready to learn who killed Joffrey at this point, but beware, there are spoilers for future episodes ahead.

The theory boils down to five shots in the first two episodes of the fourth season of Game of Thrones. Keep in mind, readers of the book may already know what happens, but any viewer who had not read the books would have been left clueless and in shock after Sunday night's episode.

Series author George R.R. Martin also wanted to make King Joffrey's death mysterious, but he did not necessarily want to make the case airtight, someone poisoned the king after all. That someone happens to be the grandmother of the woman who was about to become the queen.

1.     Ser Dontos gives Sansa Stark a necklace with seven crystals. He is the knight who was drunk at King Joffrey's nameday. Joffrey was going to have him killed until Sansa spoke up and the King made Dontos his fool. The former knight asked Sansa to wear the necklace and give his name "one last day in the sun."

2.     The camera catches Lady Olenna over Lady Margaery's shoulder as the officiate of the royal wedding says "cursed be he who would seek to tear them asunder."

3.     After the wedding ceremony, Olenna talks to Sansa to offer condolences for her murdered mother and brother, mentioning how it is a terrible thing to kill someone at a wedding. Olenna plays with Sansa's hair and touches her necklace, yes she was wearing the one Dontos gave her. In a following shot, one of the seven crystals is missing.

4.     Once again the camera finds Olenna, this time as Tyrion is reaching for Joffrey's cup of wine and she is probably looking directly at the King.

5.     So how can a crystal be poisonous? It comes from the islands of the Jade Sea and requires a special production method (read about it HERE). In the TV show, Maester Cressen tried to use the crystal to poison the Red Lady Melisandre. He drank a poisoned cup and died of suffocation, as is its effect, but the sorceress drank hers and was fine because, well, she is a sorceress.

Game of Thrones Wiki confirms the theory, stating the plot was hatched by Petyr Baelish, who gave the necklace to Ser Dontos to have Olenna slip a crystal into Joffrey's cup.

That is why Dontos urged Sansa to leave with him when Joffrey begins convulsing. Since Tryion had just became the King's cupbearer, he looks guilty and no one suspects Olenna because her family had much to gain from Margaery marrying Joffrey.

Another small detail: the "Purple Wedding" was believed to be named after the color of Joffrey's face when he died, but it is actually named for the color of the poison.