The novel is set in December 1998, with considerable references to the early months of 1979, when an earlier referendum instituting a Scottish Parliament had failed to receive enough votes.

In the novel's presentation of both periods (1978–79 and 1998–99), real estate and construction in Edinburgh is booming, with gangsters speculating on choice areas near the proposed new institution.

While on a tour of Queensberry House, which is to be incorporated into the new Parliament, the committee members open up an ancient fireplace and find a mummified murder victim.

Grieve's murder is an important case, and it is assigned to DI Derek Linford, an earnest younger man with ambition and prospects; however, Rebus prefers his own methods.

Rebus tries to learn more about the intertwining of the local mobs and real estate in the late 70s from Cafferty, but also uncovers the cancer scam and resolves to put him behind bars again.

His role in Set in Darkness led one reviewer at the time to speculate “that in a few - preferably a good few - novels' time, a convulsive final secret will see [Rebus] and Cafferty locked together, disappearing over some Caledonian equivalent of the Reichenbach Falls.”[5] Another change is the expansion of the role of Siobhan Clarke in Set in Darkness and subsequent Rebus books.