Shana Siddiqui was an entomologist. She was followed home by a Raven.
She was interviewed by Petronella Osgood to help on a UNIT case. Osgood showed her the Wirrn lava and asked her to investigate it. She examined a a cell culture from the Wirrn queen which then attacked her. She became infected by the Wirrn and started to hear voices. She was concerned and called Kirsty for help. Shortly afterwards she put down the shields and this caused Marcus to be stung. She didn't want to obey the Wirrn. When Marcus wasn't killed she suggested that Marcus was being a puppet for the Wirrn. Osgood realised that her infection was slower than the rest and wanted to use this to find a solution. Kate Stewart asked her to find out from the hive mind memories what had caused the Wirrn to die in the past. She then agreed to be injected with a Virus from the UNIT archive, but didn't die as a result. She worked as a hologram whilst Osgood tried to reverse the changes. (AUDIO: Hosts of the Wirrn)