It is 1665 and Hannah is full of excitement at the prospect of her first trip to London. She is going to help her sister, Sarah, in her candy shop, 'The Sugared Plum'. But Hannah does not get the welcoming reception she expected from her sister, because the Plague is taking hold of London. However, Hannah is determined to stay and together the two young women face the worst-with the possibility of their own demise, growing ever closer. But through it all they persevere with the support of their neighbors and each other. And at last, they find hope in a daring attempt to escape the city.