The Insidious 4 The Last Key movie is an origin story that focuses on the character Elise.
The first Insidious film was released in 2011 and earned $54 million in the United States.
Insidious 2 was released in 2013 and earned $83 in the United States, making it one of the only sequels (non-tentpole) to earn more than the original.
Insidious 3 was released in 2015 and earned $52 million in the United States.
The Insidious franchise can also lay claim to being the only franchise to have 3 studios release its first four films. The now defunct Film District released the first two, Focus Features released the third, and Universal is releasing the fourth.
Originally scheduled for release October 20, 2017, Insidious 4 The Last Key was pushed back to the first week of January 2018.