The fifth episode of "Game of Thrones" season 7 titled "Eastwatch" featured a lot of hidden hints, callbacks, and interesting details. Here are the best ones we found!

The letter Arya found in Littlefinger's room

The letter Arya finds in Littlefinger's mattress is the one Sansa wrote in "GOT" season 1. Cersei Lannister forced Sansa to write this letter to Robb Stark to ask him to swear fealty to King Joffrey.

This letter, as the showrunners explained during "Inside Game of Thrones," is part of a Littlefinger's plan to turn the Stark sisters against each other.

Rhaegar and Lyanna's secret wedding

During episode 5, Gilly uncovers information from an old book, a story about how High Septon Maynard issued an annulment for Prince Rhaegar Targaryen and remarried him to someone who is clearly Lyanna Stark. This is huge: the marriage between Rhaegar and Lyanna means that Jon is the legitimate son of Rhaegar and therefore legitimate heir to the Iron Throne!

How Jorah and Thoros of Myr know each other

The siege of Pyke was the last significant battle during Greyjoy's Rebellion.

Robert Baratheon's forces assaulted the castle, finally bringing down parts of the southern wall. Thoros of Myt was the first through the breach, wielding his flaming sword with Jorah Mormont not far behind him. Jorah earned a knighthood for his bravery, and both in the books and in the show (he talked about the siege to Barristan Selmy in season 3), he always remembered Thoros Of Myr's incredible bravery.

Gendry has a warhammer now

Gendry is Robert Baratheon's bastard son, and Robert's favourite weapon was a warhammer. As we clearly saw when he meets Jon for the first time, Gendry doesn't want to hide his parentage anymore.

Is fermented crab like Viagra?

When the Gold Cloaks catch Davos and Gendry, Ser Davos tells them that they're smuggling fermented crab. The Onion Knight then explains that fermented crab works like Viagra.

Is that true?

In real life, crabs contain a lot of zinc, which is a mineral found in most aphrodisiacs, but obviously it's not as powerful as Davos tells it is.

Gendry's father killed Jon's father

When Gendry and Jon meet each other, they talk about their fathers, but we know that Jon's real father is Rhaegar Targaryen, which means that Gendry's father (Robert Baratheon) killed Jon Snow's father (Rhaegar Targaryen) with his warhammer.

A new location has been added to the opening credits

Eastwatch-by-the-sea, the easternmost castle along the Wall, has been included in the opening titles scene. It's the Night's Watch's castle Jon reaches in the second half of episode 5.

The wheel

In the first part of the episode, Daenerys says: "All I want to destroy is the wheel that has rolled over rich and poor to the benefit of no one but the Cersei Lannisters of the world." This is a callback to what the Dragon Queen said to Tyrion Lannister in "Game of Thrones" season 5: "Lannister, Baratheon, Stark, Tyrell — they’re all just spokes on a wheel.

This one’s on top and that one’s on top and on and on it spins, crushing those on the ground".

The achievements of better men

Before leaving Oldtown, Sam tells Gilly that he's tired of reading about the achievements of better men. Thse are the same words his father used in their last meeting. Randyll and Dickon Tarly are now dead, but Samwell doesn't know it.

The wight's hand

In the books, Lord Commander Mormont chopped off one hand from the wight that almost killed him at Castle Black and sent Alliser Thorne to the capital so the King would realize that the Others are real. But when Thorne reaches the capital and finally meets with Tyrion Lannister (the Hand of the King), the wight's hand had decomposed and Tyrion thinks the menace isn't real.

This is interesting since in episode 5, Tyrion himself asks Jon to bring a wight to the capital as proof of the White Walkers' existence.

Don't forget! "Game of Thrones" season 7, episode 6 airs on August 20 on HBO.