BRUNSWICK, Maine — Tucked away in the former U.S. Navy base Wednesday morning, a Portland Police Department bomb robot reared back on its wheels, turned its “head,” and rolled toward the door of the former refitting building.

“Now he’s just showing off,” Capt. Alex Wild of the 11th Civil Support Unit of the Maine Army National Guard said. But Wild still marveled at the technology that allows the robot to scan for explosives.

Earlier Wednesday morning, as part of a multi-agency drill, dozens of teams including Maine Task Force One, the COBRA Regional Response Team and area fire departments staged a drill on a remote road at the now-decommissioned Brunswick Naval Air Station and learned what — according to Wild’s scenario — they faced nearby.

Wild, who organized the scenario, said the setup was that Marines from the nearby U.S. Marine Reserve Center marched past the decrepit, deserted refitting building on Tuesday and smelled something odd. Brunswick police officers “responded,” and then the department’s Special Response Team entered the building and encountered “some bad guys,” Wild said. Then suspected terrorists triggered an explosion in a chlorine container, causing internal injuries to the officers. Nerve damage in some first responders also was suspected after seizures were reported in patients at a local hospital.

That was the gist of the scenario. Now it was up to those assembled to figure out exactly what had happened, and whether the threat was over.

The drill offered the teams — including the Lewiston Police Department Critical Incident Team and the Maine Department of Environmental Protection — an opportunity to work together “and see what everyone’s capabilities are, and also what their limitations are,” Wild said. “It’s knowing your neighbor.”

“It’s hard to bring all these agencies together,” said Deputy Chief Don Koslosky of the Brunswick Fire Department, the incident commander on Wednesday.

After the Portland Police Department’s Hazardous Devices Unit bomb robot scoured the former refitting building for additional explosives, others tested the large chlorine cylinder that had “exploded” earlier.

Meanwhile, the U.S. Army’s mobile analytical lab tested clothing worn by members of the Brunswick Police Department’s Special Response Team when they entered the building.

It was good practice for “real world” incidents such as one in May in Ellsworth when a suspicious white powder was discovered, Wild said.

“We never found anything,” Wild said of that event, but the unit’s mobile analytical lab was able to test clothing before it was sent to the state health lab. Neither found any evidence of hazardous materials.

Later Wednesday afternoon, as first responders cleared out, Maj. Darryl Lyon of the 11th Civil Support Unit of the Maine Army National Guard arrived with more advanced equipment to try and determine the nature of the threat.

Capt. Mike Gary briefed his team, dressed in “Double A” protective gear, before they investigated the vacant Navy buildings, first checking for radiation and then moving inside and discovering a “clandestine lab,” including one used to make methamphetamine.

“The scary thing is [with] a meth lab, if you just changed a little bit — heated something up or cooled something off — you could create some seriously dangerous situations,” Lyon said. No one on his team has ever been injured while responding to such a situation, he said, but added, “If you get somebody hurt doing this job, you’re not doing your job. You have to be patient, methodical and even scientific in some cases. You try to be as risk adverse as humanly possible, based on the threat. … We can play this chess game one move at a time.”

Wild said at 7 p.m. Wednesday that the group wouldn’t leave until the team had determined what the staged threat was, “even if it takes all night.”