Details you may have missed in Season 7 Episode 5

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Gendry's weapon of choice, a warhammer, is the same as his father Robert Baratheon used to kill Rhaegar Targaryan, Jon Snow's real father.
Capturing a wight was attempted back in Season 1, which Joer Mormont sent to Joffrey as a proof.
Gilly reveals that Jon Snow is not a bastard after all, and may be the rightful heir to the Iron Throne.
Gendry and Jon greet each other like their fathers did, commenting on each other's appearances.
Sam's father snarked at him back in Season 6 that he's "spending his life reading about achievements of better men".
Cersei forced Sansa to write that note back in Season 1.