In the final months of Sri Lanka's civil war in 2009, government forces cornered the remaining Tamil Tiger fighters and hundreds of thousands of civilians into a shrinking strip of land on the northeast coast. This Channel 4 investigation pieces together what happened there using mobile phone footage shot by soldiers themselves, some of it showing bound prisoners being shot at close range, alongside video shot by the trapped civilians. UN officials, forensic pathologists, and human rights investigators examine the material frame by frame, cross-referencing timestamps and locations to establish who filmed what and when. Survivors describe the shelling of designated no-fire zones and hospitals, and the film lays out the numbers: tens of thousands of civilian deaths that the Sri Lankan government has always denied. The reporting is blunt and the footage is often hard to watch, which is the point; the film's case is that this evidence was gathered specifically because official channels refused to investigate. It remains one of the most direct pieces of war crimes journalism British television has broadcast.