The Transportation Security Administration gave a rare peek on Tuesday inside a vast security system in the basement of DFW International Airport.
A 17-mile maze of conveyer belts carries thousands of bags a day from ticket counters to planes on the tarmac.
The average time: seven minutes.
Early on, every bag gets x-rayed, and in a second, a computer algorithm automatically determines if there's anything that should be checked further.
Get DFW local news, weather forecasts and entertainment stories to your inbox. Sign up for NBC DFW newsletters.
Inspectors in another facility a few miles away look at each suspicious x-ray image, and flag some bags to be searched by hand.
"These are the unsung heroes of TSA,” said TSA supervisor Jason Smith. “What we do down here is not so much a secret. It's just out of sight, out of mind."
While an NBC 5 crew was there, TSA officers were inspecting a set of tires headed to Puerto Rico.
The latest news from around North Texas.
Nearby, other officers were searching a bag with boxes of ammunition and bottles of hot sauce.
Both items are legal to transport but understandably set off red flags.
For each bag that's inspected, the TSA leaves a card that lets passengers know they went through their stuff. Some call it a TSA “love note.”
The TSA's focus is on finding explosives.
Bag checks are just part of the process.
They also use specially trained dogs to check carry-on luggage passengers carry through the terminals.
“We do have multiple tests, internal, quality control tests, that we go through, just like with different aspects of our screening procedures,” Smith said. “We have to be right 100% of the time, and we have a really good record."
As airports gear up for busy holiday travel, TSA urges travelers to arrive at the airport two hours early for domestic flights and three hours early for international.
They also urge people to wait until they arrive at their destinations to gift wrap Christmas packages so officers won’t have to open them up to inspect them.