What Happened In Apartment Five A?
Praia da Luz is a small Algarve resort built around low-rise apartments, whitewashed villas and roads leading down towards the Atlantic.
In early May two thousand and seven, it is busy enough to feel like a holiday destination but quiet enough for families to settle into routines quickly.
Among them are Kate and Gerry McCann and their three young children, staying at the Ocean Club resort.
Madeleine is three years old, a few days short of her fourth birthday.
She is on holiday with her parents and her younger twin siblings, Sean and Amelie.
Their apartment, numbered five A, sits on the ground floor close to the edge of the complex.
In the evenings, the adults in the group eat at a tapas restaurant while periodically returning to check on the sleeping children.
On the evening of Thursday, the third of May, that routine begins again.
The children are put to bed.
The adults gather for dinner nearby.
Checks are made during the evening. Nothing about the arrangement yet tells the people around that table that one particular interval of time is about to become one of the most scrutinised periods in modern missing-person history.
Shortly after ten o'clock, Kate McCann returns to apartment five A. Madeleine is not there.
There is no immediate explanation that accounts for where she has gone.
Within minutes, people begin searching the resort. Within hours, police are involved. Before long, the image of a small girl with distinctive colouring in one eye is travelling around the world.
The question is initially simple: where is Madeleine?
Nineteen years later, the investigation has accumulated witnesses, search operations, phone records, forensic controversies, competing theories and a German suspect whom prosecutors say they believe was responsible.
Yet Madeleine has never been found, and no person has been charged over her disappearance.