Is there really a mysterious threat waiting outside their door?
Or is he simply holding her prisoner?
“We were constantly afraid,” Acker tells EW.

Lorenzo Bevilaqua/ABC via Getty Images
“This is James' 7-year-old, maybe 8-year old iPhone.
(Yep, Acker really throws her husband down the stairs).
They also got help from sound designer Jack Whittaker and sound mixer Lucas Miller.
“Life sort of takes over.
This was really a moment when life had literally slowed down.
We actually had the time.
So it was like, ‘Let’s do it.'”