"Firecracker" starts with a bang (literally) and maintains the suspense throughout. The bulk of the movie focuses on our two villains and their hostage ensconced in an otherwise empty house on Bonfire night. That's the same as Guy Fawkes night, similar to the US 4th of July in that everyone is expected to light off fireworks and make a lot of noise. Bits of backstory are blended in through some nicely done flashbacks, a few telephone conversations, and occasional visitors to the house. While there is certainly plenty of violence, cruelty, and death, it is not excessively gory. There's a steady tension throughout, and several really surprising twists in both plot and character exposition.