1) DCI Jones has been secretly surveilling a wealthy family's home for weeks, observing their movements and taking detailed notes.
2) Jones breaks into the family's home while they are away and discovers a hidden basement that has been converted into a torture chamber, with blood and tools of torture everywhere.
3) Horrified, Jones realizes the family is a group of serial killers and that he is now a target, as his name and photo are pinned to a map in the basement.
4) Jones tries to call for help but has no cell service. He hides as the family returns home and discovers someone has been in the house.