The greatest surprise was that they were still alive. All 13 of them: the Wild Boars football team and their coach.
Veteran British cave diver John Volanthen can still summon up the disbelief he felt when he found the boys, trapped for ten days deep inside a labyrinth of flooded caves in Tham Luang, Thailand, after the world had written them off as dead.
'I was incredulous. It just seemed so improbable,' he says now.
He remembers the first clue. In the ink-black darkness of the cave it was a smell — 'heavy and ripe; strong enough to twist the stomach' — that first alerted him and long-time diving partner Rick Stanton to what they assumed would be a graveyard.