The Laird Who Loved Me by Karen Hawkins

Handsome Alexander MacLean enjoyed his intoxicating flirtation with lovely Caitlyn Hurst…until she embarrassed him in front of the entire ton. Orchestrating Caitlyn’s attendance at a fashionable house party, Alexander plots her downfall. But to his fury, her charm and wit thwart his plan to ruin her.
Her disastrous London season left Caitlyn filled with regret and determined to make things right with Alexander. She’s delighted to find him at the house party to which she’s unexpectedly invited—but it’s clear that the sexy, arrogant Highlander hasn’t forgiven her. So Caitlyn comes up with a bold scheme, proposing an unusual contest drawn from legend: each must complete a set of “mythic” tasks. If Caitlyn succeeds, Alexander promises to relent and forgive her previous rash behavior; if he succeeds, she will join him in his bed! But can Caitlyn force Alexander to give up his quest for vengeance without giving up her heart in return?