Thor: Ragnarok is the sequel to 2013's Thor: The Dark World which follows Thor's adventures after the events of The Avengers. We explore more about the Infinity Stones and its usage and how it shaped the history of countless worlds in Thor: The Dark World. [Thor: Ragnarok](tag:956858) will follow up on Thor's quest on discovering what his visions meant, which he began at the end of [The Avengers: Age Of Ultron](tag:293035). Thor's return will result in another catastrophe as Loki has usurped the Throne at the end of The Dark World. Based on the title of the movie we can all assume that Surtur a demonic being from Muspelheim will make an appearance BUT will Surtur be just contributing in yet another plot by Thanos?
We all know ( I assume) that the Space Stone or The Tesseract is in Asgard after it was retrieved by Thor at the end of The Avengers. Thanos might use Surtur as a distraction to retrieve The Tesseract, As most know ,Thanos has proclaimed that he himself will retrieve each and every Infinity Stone out there after the failings of Loki and Ronan the Accuser as revealed in the mid- credits scene of Age of Ultron. It's a huge possibility that Surtur's rampage on Asgard will keep the eyes off the Tesseract ,using the rampage as an advantage he will snatch The Space Stone under the nose of the occupied Asgardians.
All this is just speculation and this may or may not happen. We all just have to wait for 2017 for Thor: Ragnarok