In 1760, Guillaume le Gentil, astronomer to King Louis XV, sets sail for India. He hopes to record the transit of Venus, but rough seas—and war with the British—make his quest more complicated than he could have imagined. In the end he will live through 11 years of adventures and misadventures, travelling from France to India, India to the Philippines, enduring illness, shipwreck, and the loss of more than he could have imagined, before he returns home.

250 years later, anxious, lonely Xavier Lemercier chances upon Guillaume's telescope in a flea market. As he looks out across the rooftops of Paris, he glimpses an intriguing woman with a zebra in her apartment. Then she walks into his office, and his life changes forever.

Xavier, a divorced single father struggling to keep his business afloat, will find meaning in pursuing the same quest as Guillaume did centuries earlier—the key to his heart lies in the transit of Venus (who, after all, was a love goddess). Part swashbuckling adventure on the high seas and part modern-day love story set in the heart of Paris, this is a time-travelling tale of adventure, destiny and the power of love.