Ann Cardwell was the pseudonym of Jean Makins Powley (1902–1966), a Canadian mystery novelist. She was the daughter of a judge from Stratford, Ontario, and wrote detective fiction during the 1940s. Her mysteries were originally published by American publishers and later reprinted in Canada and elsewhere. Although little biographical information survives, crime-fiction bibliographies consistently identify Ann Cardwell as Jean Makins Powley.

Her best-known work, Crazy to Kill, attracted renewed attention decades after its original publication. It was republished in 1990 as part of a series of rediscovered Canadian classics and was adapted into a detective opera by librettist James Reaney and composer John Beckwith, first performed in Canada in 1989

Books by Ann Cardwell:

1941 – Crazy to Kill – Mystery House (Arcadia House), New York
1947 – Murder at Calamity House – Arcadia House, New York

Collectible Book Values

Crazy to Kill (1941 first edition, Mystery House, with dust jacket) – $150–400+
Crazy to Kill (1941 first edition, no jacket) – $40–125
Harlequin #22 (1949 Canadian paperback) – $30–75
Black Cat Detective (1944) – $40–100
Macfadden paperback (1962) – $10–30
Nightwood Edition (1990) – $8–25
Murder at Calamity House (1947 first edition with jacket) – $125–350
Murder at Calamity House (without jacket) – $40–100

Values depend heavily on condition, presence of the original dust jacket, signatures, and provenance. Scarcity is greater than demand, so exceptional copies can sell well above these ranges, while average reading copies may bring considerably less.