Mounting evidence pushes Perez and the team to revise their view of missing man Connor Cairns.
The identity of the new murder victim casts doubt over whether Connor is a vulnerable missing man or a killer on the run. Rachel Cairns is horrified by the suggestion her son is involved, but Perez's interest is piqued when Abbie confesses her brother used to work for drug gangs in Glasgow.
Procurator Fiscal Maggie Kean encourages Perez to revise the missing person's case, while a facial reconstruction of the unidentified body in the suitcase leads to a possible match on the airport CCTV footage.
Later, when Connor's phone is recovered from the search area, the geolocation data shows repeated trips to an unknown remote spot in Shetland, surely Connor's 'safe place'. However, this breakthrough in the case puts one of the team in grave danger.