. >> narrator: bob pennal was in charge of the fresno meth task force. one of his jobs was to check out remote locations in california's central valley, to see if they might be home to meth super labs. on this day, he spots an abandoned barn with a mobile home beside it, an ideal location for a lab, and he decides to take a closer look. using night vision goggles and infared spotlights, pennal and his agents plan to sneak up undetected to the barn and see if there's any sign that it's been used to cook meth. >> we're just going to be going in basically to take a look at this place. we want to see what kind of smells we get. we're going to use the ir spotlight, so bruce will get in closer and we'll take a look around. >> narrator: stealth is essential to pennal, because super lab cooks can slip into an abandoned barn, whip up a batch of meth in under 48 hours and then vanish. and if they suspect that pennal has his eye on one of their favorite sites, they'll use a different barn for their next cook. >> we're going to straight down this road right here. >>