The phrase most likely refers to the 5th Wave book series by Rick Yancey or its 2016 film adaptation , which holds a 5.2/10 rating on IMDb . The series is a prominent sci-fi thriller ("Sci-FiThri") often categorized in "Top 10" lists. Guide to The 5th Wave Series
: Widely considered a masterpiece, exploring a future where humanity has become infertile. SCI-FI | THRILLER MOVIES - IMDb 5.5 / 10 Sci-FiThri...
If you are looking for other sci-fi thrillers frequently cited in "Top 10" lists that hover around a mid-5/10 rating, consider these: The phrase most likely refers to the 5th
: Earth is devastated by four waves of increasingly deadly attacks. Cassie is on the run to save her younger brother while preparing for the inevitable "Fifth Wave". SCI-FI | THRILLER MOVIES - IMDb If you
: The survivors face the "Others" in a test of the human spirit as the situation becomes even more dire.
: The final confrontation where survivors must choose between their own safety and the essence of their humanity. Other Sci-Fi Thrillers with ~5.5 Ratings