They arrived aboard six buses, complete with police escort, "sneaking" (to quote principal Mark Tan) up the long drive in silence, as instructed, to gather on the front lawn on Tuesday afternoon.
Every last one of Abundant Life School's 230 students was there, from strapping teenagers to tiny beginners, to sing for their teacher Terry Swart, starting with a traditional South African song, followed by waiata and ending with a haka.
Mr Swart, the longest-serving teacher at Abundant Life (in IT and physical education), who arrived there in 1996, and now in the final stages of a terminal illness, was clearly moved and delighted.
"It is so good to see you all," he said. "What a surprise. What a blessing.
"We have an amazing God. Don't ever forget that. I was told that I had one week. That was a month ago, and every day I give thanks that I am here. My body is working 100 per cent.