Daniel O'Connell partners with Taichi Hiraga-Keaton at London's Baker Street-based Keaton & O'Connell Assurance Investigating Office, a collaboration established in 1982. As an insurance investigator for Lloyd's of London, he frequently travels to scrutinize claims, resolving intricate cases—including murders and serious incidents—by verifying their legitimacy. After his former partner's departure, Daniel operated solo for an extended duration before forging a new alliance.

He recruited Keaton after observing his capabilities during a probe into the death of Keaton’s academic supervisor. Impressed by Keaton’s analytical acumen, combat proficiency, and diverse expertise, Daniel identified him as an exceptional partner. Their professional association spans a decade within the series' timeline.

Daniel primarily oversees office operations while delegating field investigations to Keaton, a division reflecting their working dynamic. Keaton occasionally remarks wryly on Daniel assigning the more arduous tasks. Despite his relaxed exterior, Daniel approaches work with diligence and seriousness, contributing to their consistent case-solving success. The partnership thrives through mutual support during investigations.