Millie Bobby Brown, who plays Eleven, is shown visibly distressed during a script read-through and states she is 'not ready to let go' of her character.
Co-creator Ross Duffer explained that they wanted Eleven's ending to be ambiguous, allowing her to represent the 'magic of childhood' and for other characters to believe in a 'happier ending'.
The documentary One Last Adventure: The Making of Stranger Things 5 is scheduled to premiere on Netflix on 12 January.