Yesterday’s Blood is book five of O’Brien’s series A Slip in Time, which begins in the year 2025, where we last left Daniel Kent, the deputy sheriff.

Having come across some heirlooms in an old secretary drawer, he handles each one carefully, wondering who they belonged to and how they were connected to him. After looking into his genealogy, he discovers a name on a Civil War medal which not only is on his family tree, but is the same name as his own. Puzzled, he picks up the Bowie knife next, but as he does so, he nicks his finger, causing a flow of blood to drip onto the leather case. Once the droplet in his "present time" touches the stain from the "past", Daniel is thrown into a trip he had not expected to take.

Where will Daniel land? Will he end up in a strange place and a different century than his own or will he be with Dora, his ex-wife, who has gone before him back to 1881? Dora was eager to return to the past and the love of her life, but what will she find when she arrives? Is Wade available, and if so, does he still want her?

Francine and Luke are excitedly making plans to start their family. The orphan train is once again coming their way. If they are able to get any children, Fran wonders if she will be able to stay in the 19th century and continue her life as the mother she has always longed to be. Or will the universe upset everything and send her back, leaving Luke alone as a single parent?

Best friends Ruth and Mavis still long for a man to fall in love with. They dream about a handsome stranger who will step off the steam driven train at the depot in town. Will these young women each find a suitable match in the small town of Twin Lake, or is there an unknown person waiting on the horizon for each of them?

These are the many questions that will be answered in book five. With new people arriving in town, bringing with them troubling dilemmas, life has never been more exciting in West Michigan. Through joy and sorrows, weddings and babies, arguments and bloodshed, follow the characters you have grown to love in Yesterday’s Blood.