We've met Eleven. Now meet Six. Francine is slightly precognitive, but that 'slightly' is all she needs to attract the attention of Doctor Brenner. Now trapped in Hawkins Lab, Francine realises that all is not as it seems, and her powers might be the only thing that can save her and her fellow captives.
A much better starting point for a mini-series compared to the first volume; Six has some room to breathe within the walls of the Stranger Things story, and it does so pretty well. Getting to see Hawkins Lab from the inside is interesting, especially given that, unlike Eleven, Francine had a lot of experience with the outside world first so she can see where things differ, and how everything's not quite as it seems.
There's a good give and take between the flashbacks and the current day story, establishing Francine and her 'boyfriend's' relationship before everything went wrong, and the creeping dread that something is about to go very, very wrong grows nicely over the course of the mini-series. When it all eventually does, it's with an unexpected tie-in to the series itself, and the ending is both hopeful and tragic all at once.
Edgar Salazar's artwork is fine. It's a bit pedestrian, but there's not really much opportunity for him to go mad with it anyway, given the setting. There are a few bright spots, like the glimmers into the dark future that Francine gets to glimpse, but mostly it's just labs and suburban homes. It does the job, even if that job isn't particularly rewarding.
I doubt we'll ever see these characters in the main Stranger Things canon, but it's nice to know that they're out there, and it does go to show that there are more stories to be told in this universe beyond the ones we're expecting to see.