The series was originally commissioned under the working title Invisible, with a pair of films shot during the summer of 2019 forming the basis of the first series.

The show was cancelled after four series on 16 January 2025 due to a decline in ratings.

The second series' finale, 'The War of the Rose', was released internationally on BritBox and on DVD in Germany, Australia and the US before it had ever aired in the UK.

Because 'The War of the Rose' was eventually rescheduled to air as the third episode of Series 3 in the UK, James Murray's scenes had to be reshot with Claire Skinner to avoid a continuity problem caused by the cast change, resulting in two different versions of the episode circulating internationally.

Claire Skinner joined the cast as Chief Superintendent Mary Ormond in Series 3, replacing James Murray's character following his departure.

The second series was heavily promoted around guest star Rob Brydon's appearance ahead of its broadcast.

The title sequence from Series 2 onward features a question mark that transforms into the show's ampersand, referencing the overhead view of Royal Crescent and The Circus, two listed structures in Bath frequently shown on screen.

Series 4 was originally scheduled to air in the UK in April 2024 but was delayed due to scheduling conflicts, eventually airing from 21 July to 4 August 2024, after already having started airing in Denmark in March 2024.