The Marquess Takes a Misstep by Maggi Andersen

Perilously close to losing his inheritance, he turns his back on everything that matters to him to save her.
When about to choose his bride in London, Hartley Montford, newly minted Marquess of Pembury, learns his neighbor’s niece, Lady Madeline Howard, has gone missing, Hart drops everything to go in search of her. Despite Maddie being an annoyingly frank-speaking and independent young woman who he would never add to his list of possible brides.

Hart’s estate, Pembury, is badly in need of funds. As he and his father were at odds and the estate holds bad memories for him, he prefers his bachelor’s lifestyle in London. But he suddenly finds himself in urgent need of a wife. His Uncle William, the Montford second son, has stipulated in his will that Hart must cease his rakish lifestyle, settle down, marry and deal with his obligations, by a certain date. Or he’ll be cut out of the will.

When consulted, Maddie’s groom fears foul play. Suddenly, despite the pile of unpaid bills, the renovations needed for the estate, and the clock ticking to fulfil his obligations, Hart simply cannot give up until he finds her. But in London, the popularity he once enjoyed seems to have frayed around the edges as word spreads about his treatment of Vivian Spencer, the lady he was considering for a wife.

When Maddie’s parents died, her father made her Uncle Arthur Wakeham, a cold, indifferent man who rules her with an iron hand, her guardian. When he takes up with some questionable fellows, for nebulous reasons, Maddie grows afraid for her safety. She flees with her maid to her aunt’s house in Bath.