In West Yorkshire's Wetherby Young Offender Institution (WYOI), a group of cadets wait for a prison count to be completed before they can begin their training.
Until everyone is accounted for, all movement within the prison is frozen.
It is an unusual start for cadets - but this is no ordinary unit.
"By coming here, they're joining this gang, which is a better gang," says Michael Colley, Supervising Officer at WYOI.
Many arrive from "broken backgrounds" and gang cultures, Mr Colley tells us.
Some have never owned a toothbrush or learnt how to cut their toenails.
The goal is to put young offenders on a new path with new qualifications, enabling them to step away from the social circles which put them behind bars.
The course has been going for more than 10 years but recently has been revived.
It offers basic life and organisational skills found in the British Army, which many in the group have missed out on in their childhoods.
It is funded by the prison's education service, not the Ministry of Defence, but the Army Foundation College in Harrogate help out with donations of small-sized kit and local reservist unit 4 YORKS assist with providing rations and expertise.
During the 12-week course, cadets can get hands-on military-style training.
Finally, the group gets the green light, and are allowed to leave the main building for today's lesson - how to apply camouflage paint.
One cadet, aged 17 who was convicted of a crime committed two years ago, spoke anonymously to Forces News during the lesson.
"We're going to be basically playing hide and seek," he explained in full kit.
"Two people will be seeking from a distance, the rest are going to camouflage and not get seen."
This particular young man will soon leave Wetherby for adult prison, and is expected to serve seven or eight years inside.
"It teaches you discipline - I don't have discipline yet," said another member - currently serving three years for a robbery.
One man at the heart of the cadet operation is long-time volunteer and forces veteran, 72-year-old Keith Daniel.
He is known as the prison's grandad and gives the cadets lessons in drill.
"It makes me very proud, that's why I'm still here," he said, speaking of the change he sees in many of them during the course.
"Since I met him, my manners have got a lot better," said one cadet of Mr Daniel.
"I call my mum 'Miss' accidentally sometimes, nowadays."
Many cadets are inspired by a career in the military, but upon leaving Wetherby, they must serve a period 'on license' during which they are unable to join the military.
This forces many back into the criminal gangs they came from.
Some would like to see those leaving able to serve the license period during basic military training - allowing them to break the cycle of re-offending.
"At the moment, some of these young people are coming into custody, completely turning their lives around, gaining new skills, new abilities, rediscovering themselves," says cadet instructor, Aaron Slater.
"They're then being released back into the same environment that they were committing the crimes in... which leads to reoffending.
"Let's take them from the gate, take them to a depot, get them trained up, help them desist from offending."
"If we could change the rules so that the Army would take them straight away [upon] release, that would be great," says Head of Reducing Reoffending, Stephanie Richardson.
For the staff, the sense of family felt by the cadets outweighs the risk some perceive in teaching criminals military skills.
Pass-off day sees the group parading to celebrate the completion of their course in front of proud parents and guardians.
For many involved and those in attendance, it could mark the start of something new.
"No more police, I'm tired of it," says one cadet.
"I'm mature now... there's a lot more to life than gangs and all that.
"I've missed three summers already, missed two birthdays."
"I never really look at what the young people have done," says Mr Slater.
"I like to take people at face value.
"It's the first time some of these lads have ever achieved anything, and the pride that you can feel coming from them and see around them - just amazing.
"It blows my mind.
"That is what makes it worthwhile."