28 Weeks Later (2007)

Twenty-eight weeks after the spread of a deadly rage virus, the inhabitants of the British Isles have lost their battle against the onslaught, as the virus has killed everyone there. Six months later, a group of Americans dare to set foot on the Isles, convinced the danger has passed. But it soon becomes all too clear that the scourge continues to live, waiting to pounce on its next victims.

Danny Boyle's Encore: Danny Boyle, who directed '28 Days Later' and is credited as an executive producer for '28 Weeks Later', returned to direct the opening sequence of the sequel, including the scenes featuring Robert Carlyle.
Handheld Mayhem: To achieve a realistic feel on a small budget, the filmmakers utilized a lot of handheld camera work, mirroring the documentary style of the first film. This approach aimed to make the horror feel more believable.
Movement Matters: All extras playing the infected were required to have a background in movement-based arts like ballet, dance, gymnastics, circus performing, or miming. This ensured the infected had a uniquely unsettling and animalistic way of moving.
Stadium Switch: Scenes that were originally intended to be filmed at Wembley Stadium in London were moved to Cardiff's Millennium Stadium in Wales due to the major reconstruction that Wembley was undergoing at the time.
Guilt Trip: The film explores themes of guilt and the fragility of civilization, with Don's abandonment of his wife being a catalyst for the resurgence of the Rage Virus. His actions symbolize how unresolved guilt can resurface and destroy individuals and those around them.