star Sadie Sink has teased the fourth season of Netflix's sci-fi series will be "really dark".
The US actress, 19, plays tomboy Max Mayfield on the hugely popular horror drama, after joining for season two.
Filming on season four is almost complete and while Sink remained tight-lipped on the new episodes, she hinted fans could expect a shift towards a gloomier tone from the 1980s nostalgia of earlier installments.
She told the PA news agency:
Set in the 1980s,follows a group of teens in the fictional town of Hawkins, Indiana, battling an evil monster who comes from the underworld known as the Upside Down. The upcoming season will include action in Russia, with David Harbour's police chief Jim Hopper held captive by spies.
Sink was speaking at the premiere of Netflix horror trilogy, in which she stars.
The teenage actress said the more adult tone of the films compared towas part of what attracted her to the role of Ziggy Berman.
also stars Winona Ryder, Millie Bobby Brown, Natalia Dyer, Charlie Heaton, Finn Wolfhard, Caleb McLaughlin, Noah Schnapp, and Gaten Matarazzo.
Thetrilogy will start streaming on Netflix from July 2.