Flying from France — Tim Champlin

Cousins Brad and Glen Casemont were flung into the past five times when they touched a mysterious patch of foxfire. In each time-travel adventure, the boys barely escaped with their lives as they tried, and failed, to bring back the treasure--a rare $3 gold piece they took from a strongbox belonging to Brad's father.

All five time-trips have taken only eight hours during one summer day. They were shot at, bruised, nearly drowned, crushed, and scared half to death, but the lost coin has continued to elude them. They have time for only one more attempt before they must go home, empty-handed.

This time they land 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. Thinking Alan is a teenage relative of Brad's, Johnson asks the boys to return the coin to Alan in person. Brad is elated. This is easy. Or is it?

The boys jam themselves into the rear cockpit of Johnson's Sopwith biplane so he can fly them to England for a ship home.

But German fighters attack. Is this the end? Have they tempted Fate once too often?