IT WAS a night of booze, parties, a fight, an attempted kiss and the last confirmed sighting of soldier and former Pioneer Valley State High School student Sean Sargent.
His disappearance left his family distraught as the 24-year-old, "who was trained not be found", had both military and civilian police looking for him.
For years while working in the mines it became his father Tom's second job to find him, appearing on TV shows asking for assistance, ringing friends and contacting people who said they had seen him since Sean disappeared.
Now, all of those people will come together as Queensland Coroner John Hutton prepares for the inquest and asks for 25 witnesses and investigators to give evidence, 18 years after Sean disappeared.
His father Tom described Sean as "very intelligent young man" who "never missed a day of school".
"Even when he had his knee operated on he was supposed to rest but he was out of the hospital after 9am and I dropped him at school," he said.
He said his son, who worked at KFC as a teenager, would dive in the ponds at the golf course to collect balls, climb the rafters at the school gymnasium to gather basketballs and jump off the Dumbleton Weir when it was flooding.
"He loves all of that action stuff," he said. "But he was smart too" and finished school with an OP 2 and was dux of the school.
Sean joined the Australian Air Force in 1993 before transferring to the Army where according to Tom he was trained "to not be found if he didn't want to be".
Tom said he didn't know whether his son was alive but said there was "no point writing him off" until he was proven to be dead.
For years Tom was distraught over Sean's disappearance and felt he couldn't get any sense out of civilian and military police who were both investigating.
"We haven't achieved anything in 20 years," Tom said, who has spoken to everyone he could about where his son might be.
The investigation into his son's disappearance has been a cold case for some time with no sign of life since he disappeared from an old school friend's house on Friday March 19, 1999, that is until recently.
What happened in the lead up to that night in St Lucia in Brisbane and reported sightings of Sean has again come under the spotlight as the Queensland Coroner held a pre inquest conference into his disappearance on December 13.
Tom listened to the conference from his Bucasia home and was hopeful that during the full inquest when witnesses gave evidence under oath the truth might come out.
"They're going to say what is what and we will see what happens," he said.
The inquest plan outlines the last night (Sean) was seen, when he bought a bottle of Vodka and a bottle of coke from a hotel in Brisbane at about 8pm.
He went to Benjamin Snelling's house, a school friend, at St Lucia for a party where Mr Snelling described him as "the life of the party" and it appeared he drank most of his vodka. About 11pm, Sean and three others, including Mr Snelling and Adam O'Donnell, drove to another party at St Lucia.
"On the way to the second party, there was an incident whereby (Sean) allegedly attempted to kiss and cuddle Mr Snelling's girlfriend. This led to Mr Snelling having to sit in between them in the backseat of the car.
"They arrived at the second party at St Lucia at about 11.15pm but only stayed for around 15 minutes because (Sean) allegedly got into a fight there."
They all went back to Mr Snelling's house where (Sean) commented that he "couldn't understand how the incident happened".
"There has been a suggestion that (Sean) would have been concerned about the altercation" the inquest plan reads because he had civilian criminal charges on his army record after allegedly assaulting a bouncer in Townsville in October 1998.
"(Mr O'Donnell) advised police that at about midnight, he left Mr Snelling's house to drive home," the inquest plan reads.
"He was about to start his car when (Sean) walked past. Mr O'Donnell advised the police that he said to (Sean) words to the effect 'Don't worry about it. These things happen. I wouldn't drive (drunk) if I were you'".
Sean told him he would sleep in his car. That was the last confirmed sighting of him.
On Monday morning he didn't report to the Enoggera Army Barracks and an army warrant was issued for his arrest because he was Absent Without Leave.
Since then both military police and civilian police have investigated his disappearance including searches of the river around St Lucia, checks on his bank accounts, passport, and vehicle and engine searches.
In April 1999, Tom and stepmother Ruth appeared on the TV show Australia's Most Wanted which fleshed out a few sightings from the public, one suggested Sean was living a "double life".
"Mr Sean Mann stated that he was a homosexual and he had drinks with a man matching (Sean's) description at the Sportman Hotel at Spring Hill (a gay bar) on the evening of 31 March 1999 for around 2.5 hours," the inquest plan reads.
"Mr Mann stated that the male person said to him that he was in the army and he was gay and that it was difficult being gay in the army. Mr Mann recalled the man's first name because they both had the same name."
The inquest plan noted if he was homosexual or bisexual he was certainly not open about it.
Tom didn't believe Mr Sargent was homosexual, "but there would be nothing wrong if he was", and said when asked the question if his son "could" be homosexual, Tom said yes because anyone "could be".
Another sighting was on April 15, 1999 when a park ranger spoke to a male illegally camping, with military precision, near Byron Bay.
"He stated that he spoke to a male person through a mosquito net that resembled a photo of (Sean) that he had seen in media releases," the inquest plan reads.
The other sighting was by a truck driver in late April 1999 near Junee in New South Wales, near Wagga Wagga.
He spotted two men travelling in a blue Ford Falcon, and had a conversation with the men around a camp fire for a couple of hours.
"They talked about the army and (the truck driver) thinks that the other man (not Sean) was in the Army reserves as a carpenter," the inquest plan reads.
The inquest will also look into how the investigation was carried out by civilian and military police with Coroner John Hutton having some concerns.
"Although a number of witnesses were spoken to by the authorities, only one witness statement was taken in 16 years," the inquest plan reads.
"This matter was not referred by the civilian police to the Coroner until around August (2015), and the investigation was incomplete."
There is a second pre inquest conference scheduled for February 21 followed by phase one of the inquest on May 1-5 and phase 2 on 8-12.
The second phase of the inquest will depend on whether 10 witnesses who have so far been unable to be located by police are found.