The map of San Diego County above the desk will be used to find the coastal city.

Unlock the mystery box and read the journal

Find the colored strings in the mystery box. In the journal found inside the desk, the three cities mentioned will be written in the same colors as the strings. Those same cities will also have a hook on the map above the desk. Place the matching colored string on each hook and where all strings intersect should be on the coastal city of Del Mar.