Ranger, a golden retriever, could have been a great search-and-rescue-dog except for the squirrels--but one day he unearths a mysterious box and finds himself transported back to the year 1850 where his faithful service is really needed by a family traveling west along the Oregon Trail.

Ranger the time-travelling Golden retriever and young Isaac Pope come together in 1776 during Washington's retreat after the Battle of Long Island, and Ranger stays with Isaac while he slowly recovers from Smallpox--but Ranger's real mission comes later when Isaac is sent to spy out the Hessian troops' intentions before the Battle of Trenton.

Ranger, a time-traveling golden retriever with search-and-rescue training, heads to Normandy on the morning of the D-Day invasion where he meets Leo, a Jewish boy who is hiding with a local farmer, and Walt, a young American soldier fighting to free France from the Nazis.

Once again the mysterious box takes the golden retriever Ranger back in time, and he finds himself on Robert Falcon Scott's ship, the Terra Nova, headed for Antarctica, where his mission is to save Jack Nin, a Chinese-Maori stowaway from New Zealand, from the blizzards, unstable ice, and the other hazards that lie ahead for the doomed expedition.