Tie-dye: the symbol of hippies, good times and a blast from the past. But at Bishop Strachan it means the end of the school year for the Class of 2010. It's Friday morning 7.45am, and the school's front lawn is strewn with 120 girls dressed in their sailor-style uniform shirts - but with a twist; each shirt has been tie-dyed. There are tears, screams, giggles and shouts from opposite ends of the field. Confused yet? To understand this bizarre tradition, let's start the story from the night before. Rewind to Thursday night 10.30pm - same girls, different hour and an undisclosed location. There is no official name for this marathon night of festivities. Graduating girls come together on this special night to spend their final night in pursuit of a common goal - to complete 14 tasks and to stay awake the entire night, and somehow be back at school at 7.45am the next morning for school chapel. After gathering to sort out last-minute logistics, the girls disperse in small groups for their adventures. Each adventure is unique, but strangely enough the best moment of the night is the morning when the Class of 2010 regroups. Stories are shared between the girls and the army of tie-dyed uniform shirts gathers for one more journey. The tie-dye represents change and unity, and purposely makes the graduating class stand out at the final chapel ceremony. The girls arrive with different emotions and with their permanent ink pens for their friends and teachers to sign their shirts. After the signature mash-up and many emotional hugs, it's time to line up for the final chapel processional. Multi-coloured shirts drenched in tears of sadness file into the chapel. It is the beginning of the end - but with a vibrant, tie-dyed future ahead.