Kriz was the head librarian of the University of Rago Rago 56 Rago's Reading Dome.
When the Tenth Doctor and Rose Tyler arrived, Kriz showed Rose how to take a virtual tour of the library with the mindlink devices. When the Macrobes began possessing the library patrons, Kriz helped the Doctor hide in a room full of books to be junked. The Doctor used the boring books contained therein to put the possessed people to sleep and force out the Macrobes. Afterwards, Kriz planned to have the library's technical team remove the infection. (COMIC: The Macrobe Menace)