It's more like a relay team. Raven flies to point it's trained to, where another is dispatched, and so on, each more finely tuned toward the final destination. The Maesters have a treatise in the library at The Citadal.

Here's an article that explains why Dany's knowledge of the geography of Westeros is hurting her. Instead of winning this skirmish, she could have already won the war.

Three riders is a fallacy based on an historical figure in the books. Also a dead dragon can be raised by the Night King, in which case he'd be its rider.

There are 13 episodes this season. How does episode 8 qualify as barely past the half way point?

Yes, Lord Tarly clearly said the gold was inside the gates of King's Landing.

Littlefinger.

Shield wall!!!
Vikings owns that phrase.

Divorce and remarried.

Since Sam will survive his father and brother, Highgarden will be his.

Egg. Fried.

Only two riders will be needed if a dragon falls to a bolt.

Most fan theories think Cersie and Jamie are the Mad King's children, thus the color of their hair (Tywin was dark haired when young) and their incestuous sex life (typically Targarian, as their father married his sister). Tyrion, dark hair like Tywin, is more likely his son, sharing his military savvy. His patricide…

Whip snake is really good with the sword on Iron Fist.

Martin published this book two years ago as The World of Ice and Fire, written my a maester of Old Town. It's a history of Westeros ending with Robert's rebellion. Exiactly as described my the head maester in this episode. In other words, an Easter egg for book readers.

I'd be happier with an alternative reality in which George R. Martin has already finished a Song of Ice and Fire.

Sounds like they need to talk to Ben Winters, whose Underground Airlines has a very similar premise. His novel casts a free black as a slave bounty hunter. Benioff and Weiss do well at adapting already existing material, so the novel might save them some work.

They couldn't get Eva Green?

The sign spinner posted outside Dennis' house is played by Malcolm Barrett (of Timeless and Better Off Ted). I have to assume his character will have a bigger role to play (or not, now that Timeless has been renewed for a second season).

Most famous for her AT&T commercials.

Plus she was featured on the second season (?) of Misfits.