Diana Skouris is a scientist who worked with the CDC for seven years prior to joining NTAC, where she is now a lead investigator assigned to The 4400. Partnered with Tom Baldwin, the two were instrumental in exposing the government's secret promicin inhibitor program thereby saving thousands of lives.
Although initially wary of the 4400, Diana quickly formed a bond with abductee Maia Rutledge. Their connection grew stronger, and Diana eventually adopted Maia. Now, as she adjusts to her new life as a parent, Diana struggles to remain objective in her work at NTAC while raising a 4400 of her own.