A video blogger records his new relationship - but a series of disturbing murders are also captured on his camera, and the true identity of the killer is hidden - for now.

反黑组警长肥沙（林雪 饰），不慎丢失手枪。这件事非同小可，如果手枪被匪徒用去行凶，肥沙将大祸临头。PTU（警察机动部队）警官何文展（任达华 饰）出于义气，答应一定会在天亮之前寻回手枪，带几名手下开展了寻枪行动。另一方面，却在…

A video blogger records his new relationship - but a series of disturbing murders are also captured on his camera, and the true identity of the killer is hidden - for now.