Margaret is an apprentice glassmaker in her family’s shop, unsure about the future expected of her. She certainly never expected destiny to come knocking. Berzelius is an aging man of science on the royal court, ridiculed for his obsession with the long-lost secrets of crafting magical pearls. He needs Margaret’s help with a science experiment, which could be his last chance for redemption. Then, a near-invincible enemy attacks the walled city they call home. With a bit of unexpected help, the defending troops fend off the initial onslaught, but now the city is surrounded. As the siege wears on, and food supplies dwindle, tensions rise among the townspeople. With time running out, Margaret and Berzelius must unravel the pearls’ mysteries before the city falls forever.