At the urgent request of the Continental Congress, John Adams travels to Europe, once during the winter of 1778 and again in winter 1779. Crossing the ocean in a sailing vessel in the eighteenth century is always a risky affair but is particularly to be avoided during the frigid months. When John Adams and his son secretly board the frigate Boston on a cold, snowy morning in February 1778, it is the first time either has left North America. It certainly won't be the last. Both men, especially JQA, play key roles in U.S. relations with the old, powerful nations of Europe.

In their first voyage, father and son encounter a violent storm that nearly sinks their ship. A lightning bolt hits the main mast, causing severe damage and injuring several of the crew. One man has a hole seared through his shoulder and, after three days of horrible suffering, dies and is buried at sea. It is the first time that JQA, then ten, witnesses death at close range.

During the same journey, the crew engages and captures a British vessel. John Adams, as an official of the American government, is not expected to join the fight, but he does. During both voyages, capture by the British will almost certainly bring a quick trial in London and certain execution for all revolutionaries on board, especially John Adams.

The Adamses' second journey to Europe is blessed with smooth seas, but a more urgent problem arises. The boat develops a serious leak, and all passengers must take turns pumping water for the remaining weeks of the voyage. The captain decides to land at the nearest friendly port, which is in northwestern Spain. After arriving in this remote corner of Europe, John Adams learns that there is no ship bound for France until spring, and so he makes the daring decision to try crossing Spain on foot. Accompanied by his two sons John Quincy and Charles, Adams leads a party of Americans on a journey of roughly 1,000 miles that includes a winter crossing of the Pyrenees, the rugged, snow-capped mountain range that forms the border between France and Spain.