The concert party is busily rehearsing for the evening's debut performance, but things aren't going according to plan. Bombardier Solomons desperately tries to instil some pizzazz into their closing Broadway routine, but his suggestions fall on deaf ears. To make matters worse, bearer Rangi Ram informs the party that pianist Mr. 'Lah-de-Da' Gunner Graham is on duty whitewashing stones, and is unavailable for rehearsals.

Meanwhile, Gunner Parkins has arrived at the Royal Artillery depot 24-hours late and is met by Sergeant Major Williams, who rebukes him for arriving in a rickshaw, a mode of transport forbidden under military orders. The bearer is ordered to take 'Parky' to the Quartermasters to get him kitted out.

The party writes to Colonel Reynolds, requesting that Gunner Graham be released from duty in order to join the rehearsals. He consents, much to the dismay of the Sergeant Major, who views their very presence at the depot with disbelief. The Colonel insists that the evening's performance is important for maintaining morale.

Captain Ashwood receives a telephone call from Inspector Singh, warning of a demonstration against British rule that evening. Around 500 protestors are expected to march past the camp. He informs the Colonel and Sergeant Major.

The Sergeant Major enters the party's quarters and calls them to attention, lambasting Gunner Mackintosh for his failure to control his chronic incontinence. He warns them that they are living on borrowed time, and that he intends to send them to Burma as soon as the Colonel leaves the camp.

Gunner Mackintosh returns from the toilet, informing his fellow performers that he is too ill to play any part in the evening's concert. Desperate not to give the Sergeant Major the impression that any one of their number is dispensable, the party resort to enlisting the services of the talentless Gunner Parkinson.

As the show gets underway, Captain Ashwood receives another call from Inspector Singh, advising that all men at the camp be put on duty in order to quell the unruly protestors, who now number almost 5,000.

The Sergeant Major is only too happy to interrupt the performance and order the concert party to help man the perimeter fence, still dressed in their costumes. When he hurls abuse at the crowd, he has cow dung flung back at him. Gunner Beaumont tells him he should think himself lucky, as to them the cow is a sacred animal.