After the end of the Civil War, the Baltimore Gun Club decides to apply its engineering expertise to the design of a cannon capable of shooting a projectile to the Moon.
Prompted by a mysterious Icelandic manuscript, a professor and his nephew, with the aid of a local guide, adventure to the center of the earth through the crater of a dormant volcano.
A courier of the Russian Czar must race against time and the Siberian elements to deliver a crucial message of an impeding Tartar invasion and possible treachery.