Tess (Ryan Simpkins), a teenage girl that has suffered for years from what appears to be mental instability, has moved into a new house with her mother Jessica (Annika Marks), hoping to have a new start.

Eventually, Tess is forced to confront her hallucinations and looks into a mirror and witnesses her eye color changing from blue to brown repeatedly.

While 'Tess' explores Lucy's bedroom, Sarah explains to Jessica that Tess may have a gift where she can channel spirits and let them take possession of her own body so they can say goodbye to their loved ones and move on.

Back at home, Tess is playing and singing a song (the same one Lucy made up while swinging) on her guitar; she looks up and her eye color changes from blue to brown.

[4][5] Twitch Film also praised Anguish, stating that it was "a thrilling debut from Sonny Mallhi" and that the "results are quietly horrifying and heartbreaking.

"[6] Frank Scheck of The Hollywood Reporter wrote, "Although elegantly shot, powerfully acted and possessing a forbiddingly ominous atmosphere, Anguish is too exploitative for the artsy crowd and too subtle for genre fans.

"[7] Peter Bradshaw of The Guardian rated it 2/5 stars and wrote, "Sonny Mallhi’s non-scary thriller offers neither supernatural chills nor real-world psychological insights.