Believing his long-absent father is missing and leaving clues behind through geocaching, Zig, thirteen, relies on his love of electronics, a garage sale GPS unit, and his best friend, Gianna, to search for answers.

This time the mysterious box transports the golden retriever Ranger back to the shipyards of Belfast in 1912, where a ship is being prepared for her maiden voyage, and when he saves young Patrick Murphy from being crushed by falling boards, Ranger expects to be transported home; when he is not, he knows that somehow his job is not finished--but then, Ranger has never heard of the Titanic, and knows nothing of the fate that awaits Patrick, and all...

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.

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.

The mysterious box that Ranger the golden retriever found in the garden transports him back to first century Rome, where he must rescue Marcus, a young servant boy, and Quintus, a volunteer gladiator, from the brutal world of the Colosseum.

Ranger, the time-traveling golden retriever, has landed in Viking age Iceland, where he helps a girl named Helga journey through the ash and smoke of an erupting volcano to find her father and bring him home.

This time Ranger, the time-travelling Golden retriever finds himself transported to the deck of the USS Arizona on December 7, 1941, where he rescues the young sailor Ben Hansen who is badly burned when the ship explodes--and there is a Japanese-American boy and girl in a rowboat who also need his help to find their father amid the chaos of the attack.