Why didn't Jean just possess a random Damage Control employee from the beginning and work her way up to Metzger himself?

Starting with the tank, then the helicopter, then Scorpion... Why the Rube Goldberg device of all these unnecessary steps to find out what happened to her sister? All she had to do was stand 33 feet from the front gate of the DODC and **bam**, the mystery of her sister's disappearance is solved within two minutes then she gets Metzger to jump out of a window.