On Easter Sunday 2019, eight men inspired by the Islamic State Group triggered huge suicide bombs in churches and tourist hotels across Sri Lanka, killing more than 270 people. It was one of the worst Islamic terror attacks since 9/11. Jane Corbin talks to survivors and those who came face to face with the killers. Drawing on hours of CCTV footage that track the bombers' every move, the film pieces together how the attacks were carried out and discovers how some of the bombers came from wealthy and respected families. One was even educated and radicalised in the UK. The film investigates how the Sri Lankan government received dozens of warnings in the months and years before the bombings, yet somehow the bombers remained free.