T'Lirus was a female Vulcan who lived in the 24th century. By the 2360s, she was a Doctor of Archaeology in the United Federation of Planets and travelled to planet Codis Mu VI, to investigate legends about the Integrated Field Derandomizer. Whilst examining the ruins on this world, her sensors detected a Romulan warship approaching it. She therefore contacted the USS Enterprise-D, asking for Starfleet assistance at her dig site.