De Payns had constructed the classic filature for train travel. They would follow her to the station, where one of his team was waiting on the opposite platform. When the woman descended to her own platform, the team member watching from the other platform radioed another team member waiting at the previous railway station, telling him the woman’s position on the platform. That follower would take the next train and sit where the target was most likely to enter, so that when she entered the train she suspected nothing. The job was to identify which station she travelled to two days in a row.

De Payns’ team followed the target one station north, into an area of low-rise corporate suites and medical centres with good stands of trees and parks between them. The shops were fairly upmarket without being high-end. They followed her to a modern white building with management consultants, engineers and bioscience firms on the tenant board. One of the filature team reported that she got off the elevator on the second level, where the only tenant was a Belgian bioscience company called GrowTEK.

While the filature team tracked the target’s daily movements, the DT set up the gear to make a trombinoscope of the building she lived in. The trombinoscope was basically a gallery of images, names, associates and habits of the main players and locations in an operation, collected in an operations room, and eventually converted to a book.

Having established which door was hers—2206, which translated to the second block, second level, number six—the tech team placed cameras in the green exit sign in the hallway in front of her door, so that de Payns and his team could see who was living with her or visiting. The persons of interest were followed and photographed until they could be identified.

Back at the Bunker in Noisy, de Payns used the incoming pictures and intelligence to build the body of knowledge—the dispositif—on a corkboard in one of the operations rooms.

De Payns worked on identifying the woman’s name and her work, not hidden as evidenced by a name on the letterbox and on the apartment doorbell, and confirmed by the field team’s checking of her mail. An identity not covered up could mean a deception, so the team cross-checked the declared name with utility bills and the Belgian driver’s licence.