Stephen and Yasim join forces with Russell to find out what killed Nadir. Using TIA, the government super-database that Stephen is helping to promote, they target a worker at vaccine manufacturer Kellerman-Deloit. But outside the lab, Stephen is spotted by Michael, who's on the run and thinks his brother must be involved in the disappearance of Yasim and Nadir. Meanwhile Stephen discovers the factory is linked to the murder of four leading biochemists.