A family of five are on holiday and stay in a two bedroom ground floor corner apartment in a holiday village close to the beach.
Two of the children are twins aged two and a third is a daughter aged three.
The family have flown from England with a group of seven friends for a one week vacation in Portugal.
The story takes place on the fifth day of the holiday.
At the end of a sunny Thursday afternoon, a mother retires to the apartment with the three children.
The father decides to play tennis in the holiday village with a friend and does not return to the apartment until sometime later.
The parents of the three children put their three children to bed and prepare themselves to eat out with their friends at the restaurant within the holiday village.
There are two entrances to the apartment, the patio doors facing out to the restaurant and a second roadside front door.
The front door is locked but the patio doors are not.
The group of nine adults meet for dinner at a quarter to nine at the restaurant within the holiday village.
The restaurant provides a clear view of the apartment across the swimming pool where the children are left unattended.
Regular safety checks are done on the three children by individual members of the group including the parents.
The Father conducts his check sometime after nine and the mother conducts hers around half an hour later, at which point, she realizes her three year old daughter is missing from the apartment and raises the alarm.
One of three things could have happened.
Firstly, an abductor entered the apartment and snatched the young girl from the rear bedroom in which she was sleeping.
This is supported by a witness who saw a man carrying a child away.