What Soteria really is
What happened to the empty, dead vine-filled tunnels
Whether Kali looked for Eleven again or not
What happened to the dead Demodog in Joyce's fridge
Why the Upside Down is stuck in 1983
What happened to Dr. Owens
What happened to Yuri and Dmitri
How much about the Upside Down Murray really knows
Whether the Soviets have stopped meddling with the Upside Down or not
What happened to the base underneath Starcourt Mall
How they covered up all the deaths of the Flayed when people clearly saw many of them at the Independence Day fair, not at Starcourt Mall
How they're going to explain Hopper's return
How oblivious Karen Wheeler really is
Will's connection the Upside Down beyond his abduction and possession
What happened to all the dead bodies of the Demodogs at Hawkins Lab
Why Becky Ives didn't search for Eleven in Hawkins after she left