Undercover Lies
by Mark de Castrique

“Ethel’s adventures will appeal to fans of Richard Osman’s Thursday Murder Club series and Deanna Raybourn’s Killers of a Certain Age” Library Journal Starred Review

“Ethel looks like Marple but acts like Marlowe” Kirkus Reviews

“Plucky Ethel is an elderly Nancy Drew” Publishers Weekly

Badass 75-year-old former FBI agent Ethel Fiona Crestwater goes undercover tracking down a ruthless network of criminals in this fun and pacy installment in the Secret Lives mystery series.

WWED—What Would Ethel Do?

Seventy-five-year-old retired FBI agent Ethel Fiona Crestwater is almost getting too old for a secret FBI mission—almost! Her expert investigation skills are needed again when her elderly neighbor and close friend Sarah Phelps is found dead at her home, shot in the heart, and with an unknown male body next to her.

Turns out Sarah had a secret boyfriend who apparently killed both her and himself, but evidence points to a more serious crime. Someone is targeting wealthy senior citizens, but as far as Ethel is concerned death is too high a price to pay just for being old.

Seeking justice for her friend and capitalizing on her extensive connections—law enforcement and mobsters alike—Ethel goes undercover to expose an intricate network of lies, threats, and deadly schemes that will put her at high risk—one that might cost her her life . . .

Genre: gangland crime, Thriller: organised crime

Reviews

“

Senior detectives are all the rage right now, and Ethel Crestwater is one of the best. Perfect for fans of The Thursday Murder Club series

”

Booklist on Desperate Spies

“

A traditional spy thriller, with enough violence and double-crossing to satisfy serious fans of the genre (and just enough levity to win over skeptics). This series continues to impress

”

Publishers Weekly on Desperate Spies

“

Fans of elderly sleuths will enjoy this political thriller, as well as Richard Osman’s Thursday Murder Club series and Deanna Rayborn’s Killers of a Certain Age

”

First Clue Reviews on Desperate Spies

“

A lively mystery with a droll dynamic duo at its core

”

Kirkus Reviews on Desperate Spies

“

Brilliantly intriguing . . . a marvelously complex puzzle . . . Desperate Spies is simply an excellent way to meet Mark de Castrique

”

Crime Fiction Review on Desperate Spies

“

Politics and climate issues are entangled in a complex case that still has moments of humor. Ethel’s adventures will appeal to fans of Richard Osman’s Thursday Murder Club series and Deanna Raybourn’s Killers of a Certain Age

”

Library Journal Starred Review of Dangerous Women

“

A bewitching political thriller . . . Ethel is perfectly drawn, an endearing heroine who’s clever and capable without being preternaturally competent

”

Publishers Weekly Starred Review of Dangerous Women

“

An elderly sleuth who looks like Marple but acts like Marlowe . . . An appealing hybrid of cozy mystery and P.I. caper

”

Kirkus Reviews on Dangerous Women

“

Recommend to fans of Richard Osman and Barbara Ross

”

Booklist on Dangerous Women

“

Add another wise, experienced senior sleuth to a group that includes Richard Osman's Thursday Murder Club series and even Miss Marple. De Castrique’s quirky characters and offbeat twists will appeal to Osman’s readers

”

Library Journal Starred Review of Secret Lives

Mark de Castrique

Mark de Castrique‘s mystery novels have received Starred Reviews from Publishers Weekly, Library Journal, and Booklist. The Chicago Tribune wrote, “As important and as impressive as the author’s narrative skills are the subtle ways he captures the geography – both physical and human – of a unique part of the American South.” Mark is a veteran of the broadcast and film production business. He directed numerous news and public affairs programs in Washington, DC, and received an Emmy Award for his documentary film work. His years in Washington inspired his critically acclaimed Secret Lives mystery series, featuring Ethel Fiona Crestwater, a seventy-five-year-old retired FBI agent who now rents rooms to active agents and is the smartest and most fearless of anyone in her household. The first book, Secret Lives, was a finalist for the Edgars 2023 Sue Grafton Memorial Award. Mark is also the author of the Buryin’ Barry Mysteries and the Sam Blackman Mysteries.Mark and his wife, Linda, live in Alexandria, Virginia.

View author page

Editions

Undercover Lies by Mark de Castrique is available in the following formats

97814483167243rd November 2026 X mm240£12.99
Hardback97814483167173rd November 2026144 X 222mm240,240£21.99
Hardback97814483167173rd November 2026144 X 222mm240,240$39.99
FormatISBNPublication DateDimensionsPagesPrice