Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Valhalla Rising is a 2001 Clive Cussler book in the Dirk Pitt series.Dirk Pitt has to stop an evil CEO of an oil and natural gas company in the US from establishing absolute monopoly over oil resources and supplies. It is a typical Dirk Pitt novel dealing with a countdown, bribed officials, and ruthless evil leaders. Pitt also unravels the work of a brilliant, reclusive scientist who had made great advances in oil technology, traced the history and found the remains of a Viking settlement on the Hudson River, and discovered the remains of Captain Nemo''s Nautilus and unriddled and improved its power system (a magnetohydrodynamic engine).