Five elementary school students join the choir:Ting, Hei her brother and Fun are from Mainland China; Kathy is returning from L.A.,and the 'detective' Nam is a Hong Kong local. Hospitalised after food poisoning, the suspect points to the tofu brought by Ting's mom. Incidentally the destination of the choir's visit is the tofu production base. During a field trip, they get lost in the rural hills and have to face hunger, fear and death. By accidental they find out Kathy's crayons can be burned as candles---their only hope. But as the crayon sticks dwindle away into the night, it becomes clear that if all were to survive, one of them has to make a sacrifice.....

Five elementary school students join the choir and become friends. After rushing to the hospital due to food poisoning, the suspect points to the fried tofu brought by Ting's mom. Incidentally the destination of the choir's summer exchange is the tofu production base, shifting the trip into an investigative journey. During excursion on the last day, they get lost in the rural hills and have to face hunger, fear and possible death. Only by accident do they find out Kathy's pack of crayons can be burned as candles, their last hope. But as the crayon sticks dwindle away into the night, it becomes clear that if all were to survive, one of them has to make a sacrifice before the last crayon is out...