As Paul Weeks set off from Perth for his first four week stint working in remote Mongolia, the mining engineer turned to his wife Danica and handed her two keepsakes.
The first was a wedding ring. The second, his watch.
In a gut-wrenching account of what may well have been their final moments together, Danica Weeks told CNN host Piers Morgan how her husband feared he may never return.
"He said to me … 'should anything happen to me, I want the ring to go to the first son that's married, and the watch to the second'. And I said something to him like, 'Don't be stupid, just come back and I'll give it back to you and you can give it to them'."
Weeks has not heard from her husband since. He was one of 239 passengers and crew on MH370, the Malaysia Airlines flight that disappeared less than an hour into its journey from Kuala Lumpur to Beijing last weekend.
Like so many of the families of those that are missing, each day brings a peculiar agony for Weeks as false leads are chased; erroneous news reports are filed, then corrected and theories both credible and bizarre have emerged in the vacuum of information.
"One minute it's this, then the next minute that's not confirmed, so that's the toughest part" she says. "I'm praying I can give it [the ring and watch] back to him. It's all I can hold onto, because there's no finality to it."
The intensity of the emotion of those directly affected by MH370 has been matched by the sheer incredulity of aviation experts and the public at what has transpired.
How, in this high-tech age of uber-surveillance where hundreds of satellites sweep the earth and modern aircraft have multiple communications systems with triple redundancies, can a plane vanish without trace?
Six days after it was reported missing and despite a hunt involving more than 80 vessels and aircraft, no debris has been found in the South China Sea, where the plane disappeared, or in the Straits of Malacca.
"This is very unusual, quite unprecedented," a professor of aviation safety at the University of NSW, Ann Williamson, says.
"We are talking about a demonstrably safe aircraft, an airline with a good safety record, and a very experienced pilot in the cockpit.
"After this amount of time, I think it's fair to conclude they have been looking in the wrong place."
Confirmation on Friday that an additional search area had been opened in the Indian Ocean, about 1000 kilometres west of where last contact was made with the aircraft, indicates as much. The expanded search was based on new but "not necessarily conclusive" information, White House spokesman Jay Carney said.
Inconclusive information has defined the investigation into the disappearance of MH370. But there are some facts, albeit scant and sometimes sketchy.
With 227 passengers and 12 crew on board, flight MH370 departed Kuala Lumpur about 12.41am, local time. The last transmission from the plane was at 1.07am when it was cruising at about 33,000 feet over the Gulf of Thailand and just as it entered Vietnamese airspace.
The contact "indicated everything was normal", Malaysia's defence minister Hishammuddin Hussein said.
Suddenly and inexplicably, all communication ceased, including any from the continuous ACARS data monitoring system, from a separate system that emits data from the engine; and from the plane's hig- frequency radio.
There was no mayday call from the pilots and the plane's secondary radar, which sends its location to earth-based radar stations, ceased functioning.
However, even though the secondary radar was inoperable, it did not mean that ground or sea-based radar - known as primary radar - could not pick up the plane. It just would not be able to identify it with precision.
Intriguingly, a Malaysian military radar did pick up a reading from an unidentified object flying west across the Malay Peninsula on Saturday morning.
The final blip, or plot, from the radar occurred at 2.15am and positioned the object about 320 kilometres north-west of Penang, or about 500 km from the last known position of MH370, Malaysia's air force chief General Rodzali Daud said.
The radar reading, the complete loss of communications from the plane, and the fact that no debris has been found in the area where the plane vanished all provide pointers as to what may have happened.
Malaysian authorities still believe it possible that the plane suddenly and catastrophically disintegrated, or had been forced into a rapid descent, at the moment contact was lost.
But, after six days, some kind of debris should have been found given the massive search in the South China Sea. Moreover, no signal has been detected from the black box recording
device. By contrast, remnants of the Air France jet that crashed en route to Paris from Rio in 2009 were detected within two days after a search that spanned the Atlantic Ocean.
The indications are that, mysteriously, MH370 continued to fly on after communications abruptly ended, probably on a different, westerly course from its planned route to China.
There are two broad scenarios that could explain this. Firstly, MH370 was hijacked and its transponders deliberately shut down, either by the pilots themselves or someone else on board.
Malaysian authorities have said the option is being considered, with the psychological state of the pilots being scrutinised. The suicidal commandeering of jets by pilots is not unheard of.
Then there's the theory - posited by former Qantas head of security Geoff Askew as "extremely unlikely" - that any hijacking could have been motivated by "something valuable in the plane", whether in the cargo or the plane itself.
US counter-terrorism officials are also reportedly examining a possible terrorist hijacking.
Even though two Iranian men were on board with stolen passports, Interpol Secretary General Ronald Noble has said they "were probably not terrorists". There was also a Chinese Uighur, Maimaitijiang Abula, on board.
The Uighurs, an oppressed Muslim minority from western China, have launched a series of brutal, but low-tech terrorist acts in China, including the knifing rampage by masked assailants this month that killed 29 people.
But Maimaitijiang is a renowned oil painter, with Malaysian media reports that he worked at a Swedish flight simulation facility completely erroneous and based on mistaken identity.
Malaysian authorities also deny the plane's pilots have extremist links.
Leads seem to be taking investigators to multiple dead-ends.
Even so, a terrorist link remains a live area of inquiry, and could be behind the second possible scenario that may explain why MH370 may have travelled way off course with no communications.
That is, an explosion or structural failure on the plane caused a rupture in its fuselage that was significant, but not enough to destroy the plane or send it into a nosedive.
Such an event would lead to a decompression that deprived those on board of oxygen, a condition known as hypoxia.
Previous flights have crashed after a decompression of the cabin rendered all unconscious, the plane falling to earth once the fuel ran out.
"Hypoxia … can easily reduce a highly functioning individual to utterly useless in 90 seconds," one pilot said on an internet forum this week.
Enough time, perhaps, for a pilot to attempt to turn a plane around after an emergency before falling unconscious, with the plane continuing on its new course. Another possibility is an explosion in the cargo hold from a device hidden in baggage.
Cargo typically does not get the rigorous screening that passenger luggage does. And a plane's electronic and equipment bay, where its communications hardware is usually located, is in the cargo hold.
Much has been made of a US safety regulator warning last year of corrosion and cracking around the satellite antenna of Boeing 777s like MH370 and urged remedial action be taken.
But Boeing insists that MH370 did not have the antenna that raised concerns.
Analysts have also pointed to an incident on a Qantas jet in 2008, when an oxygen tank in the cargo hold exploded midair, ripping a two-metre hole in the fuselage.
The pilots skilfully made an emergency descent to 10,000 feet, a breathable level, before making an emergency landing.
Neither of these scenarios is water-tight. If a terrorist hijacked the plane or planted an explosive device, why has no one claimed responsibility?
Given the multiple back-ups for communications in a modern plane, is it possible all communications could be knocked out by an explosion or structural failure and yet the plane continue flying?
"It's a puzzle, it's a mystery. Everything is on the table until they find the plane," Askew says.
"There are a lot of nervous governments and a lot of sad people."
For Danica Weeks, explaining the disappearance of the plane to her eldest son Lincoln, who is three years old, has been heart-rending.
"I said to him, 'You know Daddy has gone away … and on the way Daddy got lost','' she said. "And then I broke down. He is young and resilient. He said 'that's OK Mummy, I will find Daddy'."
The story Into thin air: authorities no closer to solving the mystery of what happened to flight MH370 first appeared on The Sydney Morning Herald.