Timothy O'Connell was a lifelong soldier who had risen to sergeant by dint of his ability to terrify subordinates. He was known to be violent when drunk. During the spring of 1756, prior to his regiment being restationed, Tim left his wife taking all their money with him. Upon leaving his wife he took up with Iphigenia Stokes.
Upon arriving at the home Timothy shared with his wife Francine, Stubbs and Grey encounter Finbar Scanlon, the apothecary above whose shop the O'Connells live. Scanlon says that Francine is out and seems eager to have the pair gone. Scanlon reveals what he knew of Tim's death, saying the constable described Tim's body as having been beaten badly and possibly trampled, as there was a heel-print in his forehead, and that he'd been found half in the water at Puddle Dock. Through the course of the conversation, Grey becomes suspicious of Scanlon, who seemed nervous. His suspicions appear well founded, as they discover Mrs. O'Connell had been upstairs the whole time.
Stubbs and Grey find a badly beaten Mrs. O'Connell upstairs in her rooms. Scanlon and Mrs. O'Connell explain that she came by these injuries at the hands of her husband. The two soldiers also notice that she is with child; knowing that their regiment had only recently returned, they know the child could not be Tim's. Francine refuses Grey's offer of shroud money, a small sum collected by the regiment to help a fallen soldier's widow pay for his burial, saying her pride would not let her accept it. When Grey suggests that she has a guilty conscience and Stubbs accuses her of adultery, she explains that Tim had abandoned her last spring and left her with no money, and until his return two days prior she not seen him in over a year; she felt no personal responsibility to see him properly buried. Relenting, Grey asks if she would also like to reject her widow's pension, but she says that she will take it.
Knowing about the widow's walk, Harry Quarry brings Grey into the fold about the military's suspicion that O'Connell was a spy. Under Hal's orders and through the assistance of Joseph Trevelyan, a footman in Trevelyan's employ called Jack Byrd was instructed to follow O'Connell's every move and report back, with the aim of either proving O'Connell innocent or ensuring his capture. The problem, Quarry explains, is that Jack has gone missing, leading Quarry and Grey to believe that O'Connell's death was not some simple brawl.
Quarry had a man search O'Connell's most recent place of residence, and had instructed Stubbs to give a good look over his marital residence during the widow's walk. Both found nothing that indicated O'Connell had any papers that might be from the ordnance requisitions stolen from a clerk's hole in Calais. O'Connell had not been the only suspect – there were five others – but he was the only one to turn up dead, making him the most likely option. Quarry charges Grey with the investigation, starting with a closer inspection of O'Connell's body. None of the other senior officers of the regiment could perform this service, including Quarry, as none of them had as solid an alibi as Grey's, he having only recently rejoined the regiment after his turn as governor of a Scottish prison.
The following morning, accompanied by his new valet, Tom Byrd – younger brother of the missing Jack – Grey arrives to inspect O'Connell's body. With some reluctance from the prisoners deputed to assist Grey, O'Connell is removed from coffin and shroud and turned this way and that for Grey to inspect. Upon closer inspection, Grey is able to determine that before its time laying face down in the water, the body had been left lying on its back, and after probing O'Connell's skull, Grey finds it had been kicked in during his brawl. Before allowing the body to be covered and laid back into its coffin once more, Grey takes note of the well-defined heel print in O'Connell's forehead.
Outside, Grey finds himself between the widow O'Connell – now Mrs. Scanlon – and O'Connell's most recent lover Iphigenia Stokes, arguing over how O'Connell will be buried. Stokes insists that she cared more about O'Connell, as it was she who had come and cleaned him up to make him fit for burial, while Francine was the one who paid for his coffin. With some persuasion and the timely arrival of Constable Magruder, the two women reach an agreement that Miss Stokes will repay the coffin cost, and Mrs. Scanlon will relinquish her right to choose where O'Connell's body should be laid to reset. Miss Stokes and company then carry the coffin away for burial.
Through conversation with Tom, Grey begins to wonder about Miss Stokes, as she appears to have connections outside of the country and come from a family of sailors. Tom points out that the heel-print on O'Connell's forehead had to have come from a shoe with a rounded and wooden heel, while Jack wore shoes with a square leather heel. Quarry later adds that sailors only wear wooden-heeled shoes, as leather can become slippery on the deck of a ship. It follows logically that a sailor stepped on O'Connell's face. Further investigation into the Stokes family does not turn up any incriminating evidence, however.
Grey receives word from Magruder that O'Connell's regimental coat was found at a pawnbroker's shop. Magruder had given not only a detailed description of the garment, but also a sketch of the garment that noted the lining had been unstitched in one side, all of which points to the coat's having indeed been that of Sergeant O'Connell.
At the suggestion of Sir Richard Joffrey, Quarry's elder half-brother, Quarry and Grey met with Hubert Bowles. Bowles informs them that based on his investigations, which included the other possible suspects, O'Connell is in fact the guilty party. He goes further to explain that the day before O'Connell's death, he was seen at Lavender House. O'Connell had gone to the back door of the house, asking for a man named "Meyer", but before a servant could return to say there was no such person, he had left. Bowles shows Grey and Quarry the reports that Jack Byrd had been giving his employer, Mr. Trevelyan, about O'Connell's movements.
Agents of Bowles's office had already located each of the persons that O'Connell had met with, but thus far had not found the spy master to whom O'Connell was trying to sell the stolen documents. Bowles gives Grey a letter with the Royal Seal, empowering him to make inquiries into the matter of Timothy O'Connell's death, the wording being vague enough to ensure he could do what may be necessary. Bowles suggests that Quarry apprehend Mr. Scanlon and his new wife for further questioning. Before departing, Bowels suggests that Grey continue to investigate what Trevelyan may have to do with the matter.
The Scanlons are discovered to have fled before they can be brought in for questioning, casting even more suspicion on them. Grey eventually finds Finbar on the Nampara with Trevelyan and Maria Mayrhofer, his lover, as they flee the country for India. Trevelyan explains that he believes O'Connell hadn't returned for his wife, but for a place to stash the stolen papers until he could find a buyer. Trevelyan admits that he had planned to use Reinhardt Mayrhofer as a scapegoat, setting him up with O'Connell and eventually proving Mayrhofer a spy, which would effectively remove the main obstacle between Trevelyan and Maria.
It was O'Connell mistaking Trevelyan as Mayrhofer that led him to Lavender House. O'Connell had been dealing with Trevelyan, who was posing as an anonymous middleman, but on hearing the name Mayrhofer from another source, he began to suspect that Trevelyan was Mayrhofer. He then followed Trevelyan from their last meeting place to Lavender House, which was only possible because Trevelyan had been in a rush to see Maria, and thus had not followed his usually meticulous routine of disguising himself in a green dress at the brothel in Meacham Street.
While Grey is still trying to determine who murdered O'Connell and Mayrhofer, a sickly Maria awakens and confesses to the murder of her husband. She is confused, however, by the name O'Connell, not knowing who he was.
Scanlon confesses that he and several of his friends and family beat O'Connell to death, both for what he did to Francine and for being a traitor. Scanlon had found the documents hidden in his shop and turned them over to Trevelyan, thinking it was the proper thing to do at the time.
Tim married Francine O'Connell and brought her to live in London where he joined the 46th Regiment. They had at best a rocky marriage. He was away often as a soldier and his temper was worse for drink which was taken out on his wife. Tim was not faithful to his wife often going whoring and eventually leaving her in the spring of 1756 to live with Iphigenia Stokes.
In the spring of 1756 Tim left his wife Francine O'Connell and started living with Iphigenia Stokes. It is unknown how he felt about her as he did still go out whoring, but always returned home to her. Following his murder she was who came to clean his body and make it ready for burial. And after an argument with his widow Iphigenia ensured that he was given a proper burial, even if it was Protestant.