Claire, a popular English teacher, begins to hear a low humming sound that no one else around her can hear. This seemingly innocuous noise gradually upsets the balance of her life, increasing tension between herself and her husband, Paul, and daughter, Ashley. But despite multiple doctors, no obvious source or medical cause can be found.

• Rebecca Hall
• Ollie West
• Prasanna Puwanarajah
• Mia Tharia
• Amr Waked
• Gayle Rankin
• Samuel Edward-Cook
• Karen Henthorn