However, the Verger is snooping around, taking notes to deliver to Captain Square because he is fed up with the way the Walmington platoon treat him.
Wilson suggests an idea from a Shakespeare play he once saw, where the king dressed his troops up in bushes so they could attack the offending castle.
Frazer announces that he has inherited a diving suit from a late friend of his, Wally Stewart, who died from the "dreaded bends" due to being pulled up too quickly on his last voyage.
On the day of the exercise, the Verger is still snooping from the church graveyard, using a hidden telephone to contact Square.
Frazer and Jones proceed to move down the river, and Mainwaring launches the first diversion: Wilson and Walker have fifteen rifles attached to poles and are marching up and down behind a wall.
Frazer pushes Jones' dummy log onto the bank, but he cannot get the flap open, and falls back in the river.
However, the Eastgate platoon are distracted by Mainwaring's second diversion: Walker and Godfrey have put tin helmets on a flock of sheep and have taken them up to the mill.
The synopsis remains virtually unchanged from the TV episode, although there are a few minor changes in terms of actions performed by certain characters.