George R. R. Martin’s most recent novel in the Song of Ice and Fire series appears to be where Telltale’s story game starts.
The picture that came with Telltale's tweet includes the line: ”Trackers and hunters sworn to Deepwood with clan names like Forrester and Woods, Branch and Bole” which is taken from George R R Martin’s fifth and most recent book in the Song of Fire and Ice series, A Dance with Dragons.
This indicates the Telltale game picks up in a setting well beyond the current point the HBO Game of Trhones series has reached
House Forrester is also emphasised in Telltale’s tweet, seeming to indicate their significance in the game. Given no member of this house has appeared in print or on the screen up to this point, this would fall in with rumours the game is to follow its own side story running in parallel to the show and the books.
The hashtag #IronFromIce also appears, which seemingly refers to Deepwood Motte - an area north of Winterfell near the Bay of Ice taken by the Iron Islands during the War of the Five Kings. It is here that House Glover resides, to whom House Forrester are sworn.
There’s no given date yet for Telltale’s Game of Thrones launch, though no doubt closer to that time we’ll see more solid details about the story.
In the meantime Telltale are working to bring their Tales from the Borderlands out later this year.