get at the bottom of (something)

1. To determine the cause or source of something. What is causing this water leak? Has anyone gotten at the bottom of it yet? Has IT gotten at the bottom of the crashing issue yet? I think I've gotten at the bottom of the employees' anger—they feel unappreciated by upper management.

2. To solve the mystery of something. I have every confidence that our detectives will get at the bottom of this crime. Have the cops gotten at the bottom of the explosion yet? Medical researchers are working to get at the bottom of the newly discovered contagious illness.