Every second, trillions of ghostly particles pass through our bodies without us feeling a thing. These particles, called neutrinos, are essential for the sun to shine and for the earth’s elements to form. Truly a poltergeist among particles - neutrinos have no electric charge, so they are invisible to all normal scientific equipment.

But physicists John Bahcall and Ray Davis took on the seemingly impossible quest of hunting down the elusive particles. They searched for the neutrinos in a gold mine in South Dakota using a giant vat of cleaning fluid. But no matter how many times they tried, their results would not match their predictions.

Against the odds and in the face of their colleagues’ disbelief, Bahcall and Davis persevered. Finally, the clues they needed came from detective work at the world’s deepest nickel mine in northern Canada and a giant tank of ultra-pure water inside a Japanese mountain. And their ultimate conclusion about the true nature of the ghost particle would prove even more bizarre than anyone had suspected.

Special DVD features include: materials and activities for educators; a link to the NOVA Web site; scene selections; closed captions; and described video for the visually impaired.

On one DVD5 disc. Region coding: All regions. Audio: Dolby stereo. Screen format: Letterboxed.