Joaquin Phoenix and Scarlett Johansson collaborated on the 2013 film "Her," which showcased Phoenix's incredible portrayal of a man's connection with an artificial intelligence system. The movie, directed by Spike Jonze, left a lasting impact on audiences with its poignant exploration of existential sadness and tragedy.

Initially, Samantha Morton, known for her work in the "Harry Potter" series, lent her voice to the AI character in "Her." She had been involved in the project's development and even accompanied Joaquin Phoenix on set every day. However, during post-production, Spike Jonze realized that something was missing from the film.

For reasons unknown, Jonze made the decision to replace Samantha Morton's voice with that of Scarlett Johansson. The exact reason behind this change remains unclear, but it is speculated that Morton's voice may have sounded too mechanical or too realistic, fluctuating between the two extremes.

Despite the controversy surrounding the casting change, Scarlett Johansson's raspy voice proved to be hypnotic and played a crucial role in grounding the film. Her performance added depth and beauty to the story, ultimately contributing to the film's success.

"Her" received critical acclaim, earning $48.5 million at the box office.

It achieved a remarkable 94% rating on Rotten Tomatoes and garnered several accolades, including an Academy Award for Best Original Screenplay and four Oscar nominations, including Best Picture. The film's legacy in the cinematic world is undeniable.

While the casting decision may have been disappointing for Samantha Morton, the impact and success of "Her" cannot be denied. The collaboration between Joaquin Phoenix and Scarlett Johansson, under the direction of Spike Jonze, created a thought-provoking and emotionally resonant film that left a lasting impression on audiences.