Lessee...h, orphaned niece of blacksmith, catches attention of knight. Has delusions that knight - legitimate son of baron - would offer for her. Does downright embarrassing (to reader) things to catch his attention.
H - illegitimate half brother of said knight - attempts to discourage her and, seeing that brother is toying with her and getting her hopes up, suggests he end it with her.
Uncle wants old maid niece out from under his roof, offers her to H, who wants to be member of smithing guild. H takes him up on it.
Then the next...200 pages...more or less are filled with H looking at her much as she looked at his brother I think - when she's not looking - and keeping her at arms' length. She, OTOH, gets over (sort of) her longing for his brother and just goes through the motions. Neither talks to the other - at least, not until he discovers she's good at designing (and even then, she found out by accident that he had one of her sketches and was using it to make a sword).
They have a big blow up because brother shows up and tries to press his suit (for her to be his mistress), she finds out his secret, more angst, she gets hurt, then sick, he does a bit of soul-searching while she's ailing, makes declarations, and the book ends with her just recovered from the Fever of Forgiveness or whatever authors call that ailment that brings couples of convenience together for a HEA and about to make out (having not eaten or bathed or...anything really beyond a delayed conversation).
As an aside, guy on cover, while certainly easy on the eyes, does not look like a blacksmith. Also, h grew within a chapter or so from barely reaching the top of his shoulder to her cheek resting in the curve of his neck. So maybe by the end of the book, there was enough growth that she WAS almost as tall as he was. Hahah