Light Thickens is a detective novel by Ngaio Marsh

Ngaio Marsh

Dame Ngaio Marsh DBE , born Edith Ngaio Marsh, was a New Zealand crime writer and theatre director. There is some uncertainty over her birth date as her father neglected to register her birth until 1900...

; it is the thirty-second, and final, novel to feature Roderick Alleyn

Roderick Alleyn

Roderick Alleyn is a fictional character who first appeared in 1934. He is the policeman hero of the 32 detective novels of Ngaio Marsh. Marsh and her gentleman detective belong firmly in the Golden Age of Detective Fiction, although the last Alleyn novel, Light Thickens, was published as late as...

, and was first published in 1982. The plot concerns the murder of the lead actor in a production of Macbeth

Macbeth

The Tragedy of Macbeth is a play by William Shakespeare about a regicide and its aftermath. It is Shakespeare's shortest tragedy and is believed to have been written sometime between 1603 and 1607...

in London, and the novel takes its title from a line in the play. A number of characters in the book appeared previously in Marsh's novel Death at the Dolphin

Death at the Dolphin

Death at the Dolphin is a detective novel by Ngaio Marsh; it is the twenty-fourth novel to feature Roderick Alleyn, and was first published in 1967. The plot centers on a glove once owned by Hamnet Shakespeare, on display at a newly-renovated theater called the Dolphin; the novel was published as...

.