The stakes of the wager?

Saying "I do"!

When Gabriel is awakened by the news that his riotous grandmother has lost a card game and he has gained a bride, he knows he has to act! So the viscount wastes no time in meeting Marie, his unexpected betrothed. But she's nothing like the wallflower he expected. Not least because Marie is privy to his family's deepest secrets...which he has worked hard to hide. Now he has no choice but to keep Marie tantalizingly close!

From Harlequin Historical: Your romantic escape to the past.