M is for... Mitchell, Adam

A young British man encountered by the Doctor and Rose Tyler in Henry Van Statten's subterranean museum. The wealthy Van Statten, who owned the internet, was a collector of alien artefacts which he stored in this complex.

Adam, was a computer expert, who had hacked into the Pentagon as a child - leading him to be recruited by Van Statten to curate and add to his collection. 

He tried to befriend Rose and helped her when one of the billionaire's exhibits - his Metaltron - broke loose and began exterminating his staff. The creature was a Dalek.

After the Dalek had been destroyed and Van Statten toppled from power, the museum was to be sealed up forever. Having heard him speak of his desire to see the universe and encounter some of these aliens, the Doctor agreed to him joining them in the TARDIS.

From Utah in 2012, he found himself transported to a vast satellite orbiting the Earth in the year 100,000. Satellite 5 was a news gathering / broadcasting station.

He struggled to adapt at first, but then started to explore the station's computer systems. Realising that he could exploit advance knowledge of technological developments, he attempted to transmit information back to his home time using Rose's adapted mobile. 

However, he discovered that to integrate fully with the systems he needed to undergo an operation to have a portal inserted into his cranium. 

He underwent the process but when he attempted to use it he alerted the station's Editor - who learned about the Doctor and the TARDIS through him.

After the Editor and his alien boss had been defeated, the Doctor took Adam back to his home in England, angered that he had tried to pervert the course of history in trying to exploit his future knowledge. He still had his portal, which could be opened with the click of a finger - so the Doctor advised he keep a low profile from now on.

Played by: Bruno Langley. Appearances: Dalek, The Long Game (2005).

• Langley came to fame after playing Todd Grimshaw in Coronation Street - the series' first openly gay character.