The episode cleverly plays with the "alien invasion" trope common in 1950s cinema. Father Brown eventually solves the mystery not through astrophysics, but by utilizing a young boy's comic book collection and a deep knowledge of poisonous plants.
Critics praised the "twists and turns" and the fun visual touches, such as Father Brown's brief encounter with a motor scooter. [S5E14] The Fire in the Sky
Reviewers noted that this episode allowed Inspector Mallory to show more "scope" to his character beyond his usual grumpy persona. The episode cleverly plays with the "alien invasion"