Gary, Jacko, Charlie and Adam have completed their latest tour of duty in Afghanistan and arrive at the aircraft hangar ready to be taken home, only to be told their flight has already left. Faced with waiting another 12 hours in a hot, cramped hangar, Gary decides to try and bribe his way onto an earlier flight using a pretty uninspiring collection of belongings from the boys. He's been turned down by the RAF as well as most of the squaddies in the hangar until finally he meets Cammy, a squaddie with an impeccable sales pitch and an offer Gary mistakenly thinks is too good to be true.

Following a prank that went wrong, Sergeant Thomson takes a brief break from his day off to punish Gary and the boys by putting them on kitchen duty for the Captain's important dinner. Chef works hard to keep them under control while also trying to create a dinner good enough to impress Colonel Fanshaw, the Captain's father. But when an inebriated Thomson returns to wreak havoc in the kitchen, it's left to Gary to ensure that the dinner is a success and the Captain isn't embarrassed in front of 'Colonel Daddy'.

It's been 15 years since Gary's mum passed away and his dad Martin thinks that it's finally time to scatter her ashes. Gary, Martin, Julie and Gary's aunt Margaret all set out to his mum's favourite beauty spot, but find that it's changed a lot since they used to go there. Gary needs to come up with a back-up plan but he's distracted by a series of mysterious phone calls that not only annoy his aunt and Julie, but also manages to offend his dad on the worst day possible.

Gary and his team apprehend some strange protestors at a climate control conference.

The army are looking for soldiers to be part of their new advertising campaign. Sensing a shot at fame and stardom, Gary would rather do it himself but as they're looking for teams he signs Adam, Jacko and Charlie up for the audition as well. Jacko and Adam take dramatic tension a bit literally as they come to blows during their rehearsals, so Gary has to act as peacemaker if he is to stand any chance of landing the audition and becoming the new face of the 'armeh'.