Sorry for the cryptic title, but I realise the film has only just been released in the UK and Europe and is yet to be released in the US.
I'll hide all substantial parts of my question, just in case. I don't want to spoil anything.
At the end of Age of Ultron, Thor states that 4 infinity stones have now shown up in the last few years.
By my count we have the Tesseract, from several of the first few films. The Aether, from Thor 2. The Chitauri Scepter, again from several films. And finally, we have The Orb, from Guardians.
Now, to my knowledge
Thor, and indeed none of the Avengers, should know about The Orb. I don't remember Thor visiting the Collector between GoTG and the AoU. So, how did Thor know that The Orb had appeared? Or is he referencing a different infinity stone?
I'm looking for an in universe answer, ideally.