Elizabeth Bowmar, an eighteen-year-old midwife’s apprentice in 1618 London, is haunted by a past trauma and driven by a fierce sense of justice. After delivering a child in the squalor of Newgate Prison, she swears a desperate oath to a dying mother convicted of a jewel theft she may not have committed: protect the newborn son and seek the truth. That “sinful oath” pulls Elizabeth from cramped alleys into the shadowed halls of London’s elite, where secrets are currency and mercy is in short supply. As unrest simmers in the streets and a charming adventurer crosses her path, Elizabeth must decide how far she’ll go—and what she’s willing to risk—to keep a promise before the noose tightens.
Description
The hangman’s rope in Tyburn is long. The dance, the Tyburn jig, at the end of it…short.
In 1618 London, amidst cobblestone streets crawling with danger, Elizabeth Bowmar—“the tall midwife with ice-blue eyes that helps those in need”—walks into Newgate Prison believing the ultimate challenge God has placed before her is simply surviving it. She is wrong. What waits there will drag her back toward the heart of her deepest fears.
After swearing an oath to God to protect an innocent child from unjust pain, Elizabeth is thrust into a world where secrets are currency and every truth uncovered bears a price. As riots loom and whispers of rebellion echo through London, her determination to unravel a web of deceit draws her into the city’s shadowed circles of power and privilege.
Paired with Alexander Barkley, a dashing bachelor whose reputation hides deeper secrets, Elizabeth soon discovers that the crimes she’s chasing reach far higher than she imagined—and that powerful men will kill to keep them buried. Haunted by the demons of her past, courage becomes as crucial as faith as she fights a rising tide of corruption that threatens to engulf her and the child she has vowed to protect.
Will she find the evidence she needs to expose the sinister truth and reclaim her future? Or will her vow become the very thing that condemns her?
Sinful Oath, Book One in the On The Wings Of Angels series, is a gripping Christian historical mystery where faith, justice, and quiet acts of kindness are tested in the darkest corners of 1618 London.
2025 Finalist — American Writing Awards, Religion – Christian Inspirational
“If you enjoy historical fiction with strong moral undercurrents, detailed atmosphere, and characters who wrestle honestly with
faith and justice, this book will be right up your alley.” ★★★★★ — Literary Titan
Sinful Oath has been honored with several awards, including the Author Shout Recommended Read Book Award, 3rd place in the Digital Book Today Awards, the Literary Titan Gold Book Award, and recognition as a 2025 Finalist in the American Writing Awards (Religion – Christian Inspirational).
I’m humbled by these awards and sincerely grateful to the readers, reviewers, and judges who believed in this story. I’m deeply grateful for this encouragement and for every person who has stepped into Elizabeth Bowmar’s world and helped this story find its way.
"Justice delayed for the few can still lead to justice for the many."
Inspiration
Sinful Oath, the first book in the On The Wings Of Angels series, draws its inspiration from two sources. The first is a poignant line from Shakespeare’s *Henry VI*: “It is a great sin… but a greater sin to keep a sinful oath.” It speaks to the responsibility of those in power to protect the innocent rather than exploit them.
The second is my steadfast belief in the lasting impact of small acts of kindness and everyday faith. In 1618 London, these two threads come together in the quiet, often unseen choices my characters make as they work, suffer, and endure. Their efforts to improve the lives of others, even in small ways, gradually shape them into the people God intended them to be.
"Every woman must marry to be protected and provided for. I know this, and yet I do not want a husband"
Continue the Story
For Readers & Book Clubs
Each book in the On The Wings Of Angels series is written to stand on its own, so you can begin wherever you like. But as Elizabeth and the people around her grow and change from story to story, you may enjoy following their journeys in order.
- Prequel– Black Fog
- Book One– Sinful Oath
- Book Two– Family (coming February 2026)
If you enjoy discussing faith, courage, justice, and family in fiction, On The Wings Of Angels was written with you in mind. Book clubs can find discussion questions and additional resources on my Book Clubs page, and individual readers are always welcome to get in touch. For more information…
About
Katy McWilliams traded corporate heels for slip-ons in her cozy Maine retreat, where she now writes Christian historical mysteries set in 1618 London. An award‑winning author, her debut novel, Sinful Oath—Book One in the On The Wings Of Angels series—has received the Author Shout Recommended Read Book Award, 3rd place in the Digital Book Today Awards, the Literary Titan Gold Book Award, and is a 2025 Finalist in the American Writing Awards for Religion – Christian Inspirational.