The movie opens at a cocktail party at the Reisner Institute, a Washington think tank, some time after the events of the first movie. An invisible force drags a scientist named Dylan into a nearby bathroom, where the force (implied to be a person) brutally throws Dylan around for information. Dylan mentions another scientist, Maggie Dalton, who knows the "formula" the invisible person is looking for. Apparently accepting this, the invisible person releases him, warning him not to tell anyone he was there. As soon as the invisible man leaves (or rather, pretends to leave), Dylan attempts to call someone on his cell phone, but the invisible man smashes the phone and slashes Dylan's throat. The police arrive at the laboratory to conduct a murder investigation, but the laboratory's military supervisor, Colonel Gavin Bishop, insists it is an internal military situation and the police have no jurisdiction. Fearing attacks on the remaining scientists, the lab's owner, Dr. William Reisner, employs Frank Turner and his partner, Detective Lisa Martinez, to protect Maggie, but refuses to divulge any information on the nature of his work.