In this hardbound edition of the 13th novel in the New Tom Swift Invention Series, the young inventor is called down to Helium City to investigate strange noises that seem to be coming up from deep within the wells themselves. This should be impossible because there are several miles of near absolute zero liquid helium down there. Several probes not only fail to find anything, at least one is attacked and lost. So, Tom and his best friend, Bud Barclay, undertake the dangerous mission to go down into the well to find out what is really going on. When that trip turns to near disaster, it is time to call in reinforcements. This comes in the form of an old friend who not only knows the truth must be discovered, he believes that it must be stopped at any cost!