It was the story that gripped the world: 12 boys from a Thai soccer team and their coach were trapped in a flooded cave so deep under ground a rescue was almost impossible.
Then, as the world waited along with the boys' anxious families, a brave yet difficult plan was hatched to bring the members of the Wild Boars team out alive.
It would take skilled divers from countries including Australia and even then success was not guaranteed. Days were needed to bring out the boys and there was no guarantee all of them would make it out alive.
Graphics and maps were produced of how the boys dressed in wetsuits and flippers would swim in a buddy system tethered to expert divers up and down the treacherous subterranean labyrinth to the surface.
The boys' parents were told their sons would be swimming to safety and in the global joy which erupted after the last of the boys surfaced safe and alive, no-one questioned the method of their extraction.
But ABC Australia Southeast Asia correspondent Liam Cochrane says in his new book, The Cave, the boys were in fact drugged with ketamine and handcuffed on their journey out of the cave.
It was revealed during the rescue that the boys were mildly sedated to stop them panicking during the rescue, but the truth is more complex.
The boys received far stronger drugs, and they were handcuffed behind their backs to stop them ripping off their face mask should they wake up.
"To calm nerves, the parents were told the boys were being taught how to dive and the media reported that each of them would be tethered to an air hose and then swim out with one rescue diver in front and another behind," Cochrane writes in his book.
"This was untrue.
"Those who'd been inside the flooded tunnels knew there was no way a child who had never dived before could make it through the muddy and treacherous obstacle course.
"The only hope was to sedate them, put oxygen-fed masks with silicone seals over their faces and let the expert cave divers carry them out.
"But it was crucial that the masks fitted tightly, otherwise they might drown."
Cochrane writes that among the many full-face masks procured for the rescue, only four were small enough to fit the boys and even these were likely too big for the smallest."
A boy called Note, 14, was the first to be taken out.
He was given a sedative to swallow, then injected in each leg with ketamine by Australian cave diver, Dr Richard Harris, an anaesthetist known as Dr Harry, until he fell into unconsciousness.
Note was placed into his diving suit, had an air tank strapped to his chest, and a small full-face mask fitted.
Within half a minute Note began to breathe normally and the divers handcuffed him, tying cable ties around his wrists and clipping them behind his back.
"This was to ensure that if he did wake up from his ketamine slumber, he wouldn't try to rip off his face mask, endangering both his life and that of his rescuer," Cochrane writes.
He describes Note's rescue as being held by a harness strap on his back by one of the expert divers and submerged, "in roughly the same position as a strapped-together tandem skydiver and instructor".
Note was taken through the first flooded chamber like this, then brought to the surface where he was medically checked.
He was then taken again underwater in the tandem position for the next flooded chamber.
"The two biggest dangers underwater were the boy waking up and panicking, or his mask leaking and turning that plastic and silicone bubble of life over his face into a death trap," Cochrane writes.
"Preventing the mask from becoming dislodged was a constant concern."
The rescue was slow, difficult and physically challenging for the rescue divers, but it worked.
Note was hauled onto dry land, checked by doctors and deemed okay.
One down, 12 boys and a coach to go.