A few more idle days were passed in the torpor of heat and false security, before the great storm broke out, engulfing at once some of the small European communities in India scattered over the country, surprised and defenceless, while others for a time endured only the bitterness of expectation. Rumours of the outbreak at Meerut and Delhi reached Mustaphabad in a few hours, and to the horror and indignation aroused by the first news, there soon followed unspeakable dread and suspense as the tidings came from one station after another of treacherous risings and murder and anarchy, and those who had so far escaped felt that the same catastrophe might at any moment overtake themselves. Here, as in every place where there were both white and black troops, the gravity of the situation was vastly aggravated by the difficulty of framing a plan of action; for to make preparations might have been to accelerate the outbreak. And the position of the officers of the native regiments was peculiarly embarrassing; for while they seemed to be regarded by the rest of the community as if in some way unwittingly the cause of the calamity, and shared for the time the odium aroused by the misconduct of the sepoys in other places, they for their part were not only precluded by their position from taking the precautions which the other European residents made, against a treacherous outbreak of their men — they would also certainly be the first victims. Right bravely, however, they faced the danger, professing unlimited confidence in their men — a confidence which, whatever they felt, they exemplified by sending their beds down to the parade-ground, and sleeping there unarmed in front of the men's huts on the edge of the plain, the armed sentries marching to and fro beside them. 

Such was the building which was now to be defended. Large, airy, and massive, and standing in its own grounds at a distance from other houses, one better adapted for defence could not have been found in India; and although the additional works improvised in the emergency were of a very simple kind, consisting mainly of the sandbag wall, which, as already described, had been erected round the outer edge of the verandas, the building presented a formidable obstacle against the attack of any enemy unprovided with guns. This sandbag parapet had been made seven feet high, with loopholes at a height of six feet from the ground. The portico had been enclosed in the same way, and gave a partial flanking defence to the north side of the building, while on the south side a similar advantage was more effectually given by the detached bath-house. Here no sandbag parapet was needed, the building being surrounded externally by a bullet-proof wall to the height of seven feet, in which loopholes had now been driven, while a sandbag parapet, erected on the circular rim of the well attached to the bath, brought this all-important element of the supplies within the line of defence. A trench of communication had been dug between the two buildings, the earth from which had been thrown up as a parapet on either side, but progress had been slow in the hard soil, and the trench was but a shallow one, forming imperfect cover. An opening left in the rampart of the south veranda gave access to this trench, a lane of sandbags leading to it down the steps. The landing at the top of the north flight of steps was also protected by a parapet, so as to cover the entrance to the guard and store rooms, an opening being left to give access to the portico. 

This completed the defenders' works, save that such of the numerous massive folding-doors as were not needed for communication about the building, and which usually stood open (privacy being secured by light hanging screens and curtains), were closed for the occasion. The strength of the building as thus set out was evidenced by the cautious manner in which the assailants had begun their attack. The persons who had taken refuge in the building, and composed its garrison, were as follows: — 1°. Falkland, Sparrow, and two East-Indian clerks belonging to the residency office. To these must be added the American missionary, Mr. Jabez P. Hodder. This gentleman had been deaf to all the entreaties made him on the outbreak to leave the mission-house, which was in the heart of the city, and his wife had refused to leave her husband; and they had held their ground at the mission until the émeute in the city of the day before, when some of his native catechists had carried him and his wife away, almost by force, till they fell in with Falkland's party returning from their fruitless errand, and committed the steadfast pair to his charge. 2°. Brigadier Polwheedle, Captain Buxey, and Major Peart from the cantonment staff, and a Mr. Layton, who kept a general store in cantonments. 3°. Major Dumble and eight officers 76th N.I. 4°. Seven officers 80th N.I. 5°. Two officers 82d N.I., the survivors from the massacre of that regiment. 6°. Drs. Maxwell, residency surgeon, and Grumbull of the 76th N.I. Total, thirty Europeans, of whom, however, the brigadier was not effective for work. Of native combatants there were — the commissioner's jemadar. Ameer Khan, and four orderlies, and the seventeen faithful sepoys of the 76th, or twenty-two in all. Thus there were fifty-one effective combatants altogether. Six of the commissioner's servants, including his old butler, were still present of those who had promised to stay, and one native groom had been retained in charge of the horses picketed under the portico.  

The man now sent in another petition, this time in his own name, containing numerous specific accusations against his commandant of irregular transactions in regard to the regimental accounts, improper dealings with the native banker of the regiment, and above all, that he had drawn pay for troopers in excess of the number enlisted, for many months after the regiment was first raised. On this petition being received at headquarters, an order was issued from the adjutant-general's office to Sir Montague Tartar to convene a court of inquiry, composed of the senior officers at the station, who had Colonel Kirke and the regimental records under examination for many days, and called numerous native officers and troopers of the regiment as witnesses. Kirke at first made light of the matter; it was a mere conspiracy of a scoundrel, who of course, after the manner of his race, was ready to swear to anything — a scoundrel whom he should have got rid of long before, and would get rid of now. For although no witnesses were present in the room where the ressaldar had been received by his commandant, the orderlies in the verandah heard the voices in altercation, and on their evidence the court-martial held upon the native officer found him guilty of insubordination, and he was dismissed the service — those not being times, just after the mutiny had been suppressed, for passing over breaches of discipline in the native army.  

While the novel primarily focuses on Anglo-Indian society, several Indian characters are essential to the plot, particularly in the context of the military struggle and the eventual downfall of Rupert Kirke.

The most prominent Indian characters include:

• Ameer Khan (The Commissioner’s Jemadar): He is one of the most consistently loyal and respected Indian characters. He first appears as the dignified head man sent to meet Olivia in Calcutta. During the siege of the Residency, he is in personal attendance on Colonel Falkland and performs several heroic acts, such as cutting off the hand of an insurgent attempting to scale the portico. He also undertakes a perilous scouting mission into the rebel camp to bring back intelligence. He is the last man to fall during the relief of the Residency, killed just minutes after the death of the master he served so faithfully.
• The Nawab of Mustaphabad: A prince who remains "stanch" to the British despite significant pressure to join the rebellion. He offers his palace as a refuge and provides supplies to the garrison. His loyalty leads to his imprisonment by his own brother during the height of the rebellion. After the siege is lifted by Kirke, he is reinstated to his authority.
• The Nawab’s Brother (The "Rebel Nawab"): He serves as a primary local antagonist. He raises the flag of rebellion in Mustaphabad, assassinates the Nawab's minister, and imprisons his brother. He is responsible for the "horrible mutilation" of a British messenger. Following the relief of the Residency, he is captured by a detachment under Lieutenant Egan and, after a brief drum-head court-martial, is executed by Kirke.
• Futteh Khan (Ressaldar): A "swaggering young Patân" and native officer in Kirke's Horse, he is instrumental in the novel’s final act. Though he fights bravely alongside the British, his relationship with Kirke sours after a public reprimand. He eventually triggers Kirke’s ruin by sending a petition to the commander-in-chief alleging financial irregularities and the theft of captured jewels, which leads to Kirke’s court-martial and subsequent flight.
• The "Faithful Seventeen" Sepoys: This small detachment of the 76th Native Infantry refuses to join the mutiny and returns to the Residency to defend their officers. They are described as the "real heroes of the defence" because they maintained their loyalty at the cost of breaking all ties with their old comrades and villages. Each survivor is eventually promoted to a native officer in the newly raised Mustaphabad Levy.