When Emma Watson is in a movie, you know we're already like "Accio tickets!" no matter what. Add Ethan Hawke and another "Harry Potter" alum, David Thewlis, and you have "Regression," a dark thriller whose first official trailer just came out and gave us the heebie-jeebies.

In the movie, directed by Alejandro Amenábar ("The Others") and scheduled for an August 28 release, Hawke plays a detective investigating the case of a young woman (Watson), who accuses her father (David Dencik) of an unspeakable crime. When the father unexpectedly admits guilt without remembering what really happened, a renowned psychologist (Thewlis) is brought in to help him relive his memories. A horrifying nationwide mystery is revealed, and it's all teased in this trailer.

So here's 2 minutes of murky mystery -- plus Emma working an American accent:

What do you think? Are you in?

Want more stuff like this? Like us on Facebook.