Netflix's Bird Box movie doesn't currently have a sequel in development, but the movie's story leaves the door open for more stories to be told. Based on the 2014 novel of the same name by Josh Malerman, and with a script from Arrival's Eric Heisserer, Bird Box is directed by Susanne Bier and stars Sandra Bullock as Malorie, Trevante Rhodes as Tom, Julian Edwards as Boy, and Vivien Lyra Blair as Girl, along with many other top-tier actors and actresses.
In the post-apocalyptic thriller, Bullock's Malorie embarks on a two-day trip to take her children - Boy and Girl - to safety. Interestingly, though, Bird Box takes place in two time periods: one during society's collapse from The Problem and in the present day (five years after the monsters first appeared). While nothing is shown between the two time periods, Bird Box's core story is about the river journey Malorie takes to a supposed haven. And when she gets there, unharmed by the monsters, she names Boy and Girl as Tom and Olympia, respectively - and that's how it ends.
Since Malorie and her children make it to the safe haven - a one-time school for the blind - it seems that her story is done, but that doesn't mean a Bird Box sequel can't still happen. It's important to note that Bird Box's monsters weren't ever shown to viewers, and there's still quite a bit that people don't know about the so-called Problem (as it's named in the book).
From where the movie leaves off, a potential Bird Box sequel could either take place 10 years later (if not longer) and follow Tom and Olympia as young adults, showing how they've managed to live at the school for the blind if society has managed to fight back against the monsters. Another possibility is to explore the five-year gap between when society first collapses and when Malorie begins her journey down the river to the safe haven. Of course, it's possible a Bird Box sequel could follow another group of survivors, but it's always best to stick with established characters for sequels, especially for a movie like Bird Box.
While a typical sequel is probably out of the question since Bird Box neatly wraps up Malorie's story, the fact that the movie incorporated a five-year time gap, as well as had two young children in the film, gives the filmmakers the ability to explore multiple avenues with a Bird Box sequel. After all, there's still quite a bit about Bird Box's world that remains unknown; what are Bird Box's monsters and what do they look like? Have survivors found a way to fight back against the monsters? And why are some people affected by the monsters differently? Again, Netflix doesn't have a Bird Box sequel in development yet, but the way the story left off and considering how successful it's been so far, that should change.