Married in the Morning

Leo, Lord Ramsey, must marry and produce an heir within a year, or else — farewell family estate.
In this situation, the head of the Hathaway family has no special choice. The problem is that he has no candidates willing to... agree to such a hasty marriage. There is only one option left: to immediately marry the companion of his younger sisters, Miss Katherine Marks.
On one hand, for Katherine, this marriage could be a great match: she is as poor as a church mouse, but she is smart and beautiful. But on the other hand... there is one small complication: she and Leo hate each other with a fierce hatred and only exchange barbs.
What could come out of such a strange marriage? The very first kiss makes Leo suddenly believe: a lot of good. Of course, if he puts in enough effort to win over his own lawful wife...