Wanda Rothman was a scientist who studied nuclear reactions. Her team found vodium, which she believed could be used as a source of low-waste nuclear energy.
In 2010 she was at a conference to show off the vodium. During the demonstration she accidentally activated it, which caused it to produce micro-wormholes. These wormholes started pulling in people from the hotel, though she didn't realise the connection. Once the Eighth Doctor revealed the truth, she helped him neutralise the vodium. (AUDIO: Situation Vacant)