When twins Holly and Dylan Meredith go missing, Family Liaison Officer Lisa Armstrong realises her connection to the family might be more than just professional.

With the Meredith family reeling from Dylan's death and Sean's arrest, Lisa is charged with investigating Sean's alibi and makes a game-changing discovery.

Nick Mooney has gone missing, Holly's backpack has been found, and Lisa's children both get into trouble.

Questions remain as to how much a seriously injured Nick knows about missing Holly.

Despite what Holly tells the police that she killed her brother, they believe there's is more to the truth than she has told them.