Dr Lydia Betancourt was a 39th century scientist who worked for Professor Charles Feige on Zoda-Kappa.
Upon realising that Feige was infected by the Holomorph, Betancourt and Talia Rue began stealing equipment to build psionic inhibitors and work on a transmitter to cure the infected. Betancourt placed an inhibitor on Hebe Harrison and relieved Feige of command before working with the Sixth Doctor, Melanie Bush and Sakho Cato to complete the transmitter. (AUDIO: The Dream Nexus)