Was Valve once developing ideas for a four-player, co-operative fantasy adventure game? Artwork by former employee Drew Wolf suggests so.
Wolf's "Untitled Fantasy Game" gallery on his website shows character work for an internal R&D project, "a fantasy adventure game centered around cooperative combat and driven by story".
"The goal was to present as many groups of four adventures as possible in order to establish a diverse cast of archetypal characters. After discussion and feedback the group was paired down to ten characters. They would become the project's main characters."
The characters range from knight to demon to wraith to hunter. They're a diverse bunch.
Nowhere does it explicitly say this internal project was Valve's but Drew Wolf isn't known to have worked anywhere else in recent years. He worked at Valve, past tense, for nine years, but is now independent according to his website bio, though his LinkedIn profile lists him as at Valve still.
While at Valve, Wolf "developed a visual style for characters in Dota 2", which is where you probably know his art from.
There have been a few high profile departures from Valve of late. In May, one of the studio's most recognisable faces, Chet Faliszek, who was instrumental in shaping Portal and pushing virtual reality, left Valve. A few months earlier, Portal, Left 4 Dead and Half-Life 2 episodes writer Erik Wolpaw left Valve. His writing partner Mark Laidlaw had left Valve early in 2016, and in August 2017 would go on to reveal what was probably the plot for Half-Life 2: Epiosde 3.