How does the Giver plan and explain Jonas disappearance?

Jonas plans to leave secretly in two weeks at midnight and head for the Annex while leaving a note for his parents that he will return in time for the Ceremony, while the Ceremony distracts everyone from his absence. The Giver will call for a vehicle and driver, and The Giver will leave in the vehicle with some food and Jonas inside while the driver is distracted. By the time he returns without Jonas, he will go to the Auditorium and announce to the panicked population that Jonas was lost in the river while performing a Ceremony of Loss.