Brad and Glen have landed in World War I France at the aerodrome of the LaFayette Escadrille, where American volunteers are flying biplanes in the fight against Germany. By a twist of good fortune, a pilot named Conrad Johnson, has the gold piece. He’s planning to mail it to Brad’s great grandfather, Alan, who found it in a creek bed a few months before.
Cousins Brad and Glen have failed four times to recover a rare coin they lost. The valuable $3 gold piece, belonging to Brad’s father, continues to elude them as they adventure back to different times and places. This time, they land in the Yukon in December 1899 where a Northwest Mounted Policeman desperately needs their help.
First cousins, Brad and Glen Casemont, are back from their third time travel adventure, bruised and battered, having jumped off a speeding train being hijacked by Union spies in 1862. But, once again, they couldn't bring back the $3 gold piece belonging to Brad’s dad.
From inside a cave, Brad and Glen have gone back in time twice. During each adventure, they see the $3 gold coin, or get it in their hands, but not for long. They can’t seem to bring it back to the present. Even though they have no control over when or where they go, they try a third time and are carried back to April 12, 1862, where they land aboard a train near Atlanta.
Brad and Glen have had quite a day. Transported back in time to 1854, they landed on a steamboat moving down the Mississippi River. When they left, they had the 1854 $3.00 gold coin Brad had "borrowed" from his dad's strongbox. Problem is, they made it back to their own time, but the gold coin didn't.
In the thick woods of nearby Chicamauga National Battlefield, his cousin, Glen, slides down into a limestone cave to hide the gold piece for Brad to find. In the dark, he bends to place the coin on the faint glow of foxfire from a piece of rotting wood. Before he can stand, he gets dizzy and faints. When they wake up, they discover they are on a steamboat in 1854.