The father of three children is falsely imprisoned, accused of spying,
and the three are set out to prove his innocence. In doing so, they are
obliged to move to a place near a railway station, where they meet an
Old Gentlemen who rides the same train every day, and helps them in
their quest. They also befriend a Russian exile who has been persecuted
by the Tsar for his writings in support of poor people, and the grandson
of the Old Gentleman, who is badly injured in a railway tunnel. This
classic of young people's literature influenced many subsequent authors,
and continues to be a vivid reading experienced to this day.