Magnum joins forces with a hard-nosed private eye from St. Louis whey they find themselves investigating the same case but from opposite ends of the spectrum.

Magnum finds himself working with anachronistic gumshoe Luther Gillis again after someone kidnaps Higgins and Luther's secretary.

While Magnum is preoccupied with a very difficult case, help arrives just in time in the person of Luther Gillis, the hard-nosed private eye from St. Louis.

Magnum is elected Local P.I. of the Year, yet his award presentation as well as his investigation into a murder is hindered by the intervention of Luther Gillis and Tracy Spencer.

Higgins is stalked by a mysterious killer whose game plan is to obtain Robin Masters' newest manuscript, and Luther Gillis, the St. Louis private eye, helps to muddy mysterious waters with his unwanted assistance.