The intrepid series “Digging for the Truth” (8 p.m., History) returns for a fourth season with two new hosts, adventurer Zay Harding and former Navy pilot Hunter Ellis.

As you can surmise from the title, “Digging” puts great emphasis on archaeology, but the hosts consult experts of every stripe on their way to ferret out new facts about man’s past.

The season kicks off with “Neanderthal!”, a revisionist look at the ancient primate relatives of modern man who lived in Europe for more than 300,000 years before being displaced by our human ancestors, the Cro-Magnons.

Harding consults DNA experts to determine just how close we are to Neanderthals, as well as forensics experts who create three-dimensional, virtual-reality models of Neanderthal skulls. He also goes on a comparative hunting expedition using Neanderthal and Cro-Magnon weapons to learn and demonstrate the different skill sets and mentalities of the two groups.

We don’t discover how the Neanderthals disappeared, but we get to speculate how and where the last few spent their days. And we find an ancient Neanderthal cave off Gibraltar, now located hundreds of feet under ocean water. Gee, underwater paleontology! That sounds like the inspiration for a whole new cable series.

Over the course of the season, “Digging” will look for secrets of the Great Wall of China, King Midas, buried religious treasure and Stone Age royalty.

¢ The documentary “Inside America’s Empire,” a segment of the “America at a Crossroads” series (9 p.m., PBS, check local listings) examines the global reach of the U.S. military. While much attention is given to soldiers in Iraq and Afghanistan, “Empire” looks at American forces in countries including Colombia, Mali, the Philippines and the former Soviet republic of Georgia. Their current missions seem to be more about logistics and humanitarian efforts than warfare. But that, according to correspondent Robert D. Kaplan, could change.

The circumstances and technology may reflect the 21st century, but the strategy of empire echoes down through the centuries.

“The essence of empire is not fighting,” says Kaplan, “but rather training indigenous forces to project power on their own, in their own interest and in your interest.”

Tonight’s other highlights

• Mike Rowe works overtime on a “Dirty Jobs” (8 a.m., Discovery) marathon running all day and prime time until midnight.
• Catch up with the first five episodes of the engaging legal thriller “Damages” (2 p.m., FX), starring Glenn Close and Ted Danson.
• U.S. Open tennis coverage (6 p.m., USA).
• “History Detectives” (7 p.m., PBS, check local listings) looks at items that may be linked to Bill Pickett, President William McKinley and Adolf Hitler.
• Kyle, Jessi and the Tragers search for answers on the season finale of “Kyle XY” (7 p.m., Family).
• Held hostage on “Heroes” (8 p.m., NBC).
• Brenda must testify on “The Closer” (8 p.m., TNT).
• Justin Timberlake performs in concert (8 p.m., HBO).
• Scheduled on “Dateline” (9 p.m., NBC): Wild Bill Stanton.
• Anthony Bourdain visits Hong Kong on “No Reservations” (9 p.m., Travel).

Cult Choice

Exotic dancers stop at nothing in their search for buried treasure in the 1965 exploitation favorite “Faster Pussycat! Kill! Kill!” (2:30 a.m., TCM), directed by Russ Meyer.