Before the crashEdit
Zach, previously known as Isaac, was born to a drug addict, Holly. One day she became so desperate for money, she offered to sell Zach to Olivia and Nick. They both accepted. After Holly was taken into hospital, Zach was realised to be missing, so Olivia, Nick and Zach moved from Florida to Los Angeles.
They lived there happily for three years until Holly returned. However, she was killed and buried in the garden.
Zach and his family continued to live in Los Angeles for thirteen more years afterwards. ("The Blackmail Letter")