Mystery for Ages 10 and Up A YOUNG MAN IS GONE is the first novel in the Double-Twins Mystery Series, featuring two sets of boy-girl twins: Mark and Mandy Cousineau from Ohio, and Alex and Aggie Burke from North Dakota. High school junior Bobby Swenson had the world at his feet in 1964: handsome and popular, he was also a varsity letterman and first-rate student. When Bobby fell to his death that year at the Foxtrot-Zero military construction site,...