Seattle author Kate Breslin returns to an era she’s written about before for her new historical romance, “Far Side of the Sea.” In fact, the featured couple in “Not by Sight,” Breslin’s earlier book about World War I, both make an appearance in this new offering.

But this story centers on another member of the family. While fighting in France, Lt. Colin Mabry had sustained a series of devastating injuries and had to have his hand amputated. He’s come back to England and still serves in the military at a desk job, decoding messages sent from the front by carrier pigeon.

But one day, the message he decodes is a personal plea addressed directly to him: “Urgent you remember your promise of love. Meet me Café de la Paix, Paris… You’re my last hope. – J.R.”

Colin surmises that this message is from Jewel Reyer, a young Frenchwoman who a year earlier had saved his life by tending to his wounds and hiding him from the Germans. They had a chaste romance, but Colin returned to his regiment once he had healed.

Later, when he’d heard that her village had been annihilated during a brutal battle, he tried unsuccessfully to locate her.

Colin had assumed that Jewel had perished, but this cryptic message gives him hope that she is alive. He is determined to go to her, even though his colleagues warn him that Jewel’s father, Jacob Reyer, is on an enemy watch list. Another J.R. — this might be some sort of trap.

Colin promises to be cautious. He is given leave to find out what is really going on.

But in Paris, yet another J.R. — Johanna Reyer — meets him at the appointed time and place, claiming to be Jewel’s half-sister.

Johanna has Jewel’s diary in her possession, which is how she came across Colin’s name. But later passages in that diary seem to suggest that Jewel was being duped by a German agent.

Johanna believes that Jewel is alive, and may now be in jeopardy. She asks for Colin’s help to locate her because — here’s the catch — Johanna has never met her half-sister. In fact, Johanna isn’t even French. She was born in Ireland.

Colin has many reasons to be skeptical of Johanna’s story. But she does have Jewel’s diary, and she does bear a close resemblance to Jewel.

If there’s even a small chance of being able to repay the tremendous risks that Jewel undertook for him, he feels he must accompany Johanna, at least until he can ascertain more.

Their search has them careening across France and Spain. They soon find that their quest ties in with a treacherous international scheme that involves undercover agents, double agents and agents gone rogue. Readers may find it challenging to track the cloak-and-dagger details.

The author further endows this tale with faith-based encouragement and romantic sparks.

“Far Side of the Sea” is an ambitious effort, but readers, not unlike Colin, will be required to suspend their disbelief.

The Bookmonger is Barbara Lloyd McMichael, who writes this weekly column focusing on the books, authors and publishers of the Pacific Northwest. Contact her at bkmonger@nwlink.com.

Far Side of the Sea

By Kate Breslin

Bethany House

384 pp

$15.99