Mardock is a companion of The Beginner since End of the Line and infact is his first one onscreen one.
It all started in a spaceship when Mardock used the SOS signal to trick someone to arrive to his aid, when infact, he was a prisoner and everyone else died. The Beginner recived the signal - leading the TARDIS to end of the vortex and the end of all of time and space as he knew it. Upon rescuing Mardock, he ran out of the room and locked him in. He did this various times - until Mardock realised the Beginner was more cunning than he looked (and sounded) and in the end he told Mardock to run into his TARDIS. (End of the Line).
His first travelEdit
The Beginner lands in Statuerama Park - where he unsurprisingly encounters statues. Mardock speculates that they aren't statues and the Beginner agrees, however he doesn't allow Mardock to destroy one with a hammer, and melts it. They duo both blink and a statue grabs onto the Beginner, so Mardock grabs the sonic walking stick to unmelt it and smash the statue. The Beginner puts The Rock Kind's life source into Mardock's injured leg, allowing it to stop hurting and the statues to be harmless. (Return of the Rock Kind).
Mardock was dragged along with the Beginner for him to do the Test of the Time Lords, which the Beginner ran away from (as well as the Time War). He is met by Sir Grofi who proceeds to teleport them into the test. Mardock and the Beginner do well until they reach a series of doors which would kill if they open the wrong one. (Test of a Time Lord Part 1).
The Beginner is able to find out the door and carry on with Mardock. Mardock assists the Beginner and even helps him find a key to a door. When the Beginner aquires the brick which completes the test, he and Mardock are teleported back. They get back into the TARDIS and leave for more adventures. (Test of a Time Lord Part 2).
Cyber-Trouble & The End?Edit
The Beginner asks Mardock whether he's had enough or not, and Mardock insists that he wants to continue the adventure. They land in a Conversion Chamber and are met with a Cyberman. The cyberman tries very hard to convert the two, but fail. However later the Beginner is pushed into the conversion chair and begins the conversion process. Mardock grabs a glass bottle with liquids inside and smashes the Beginner on the head with it, stopping the conversion process. (Convertion).
Mardock was left behind whilst the chamber was destroyed, and it's presumed that he survived due to the Beginner soon meeting a relative of his in his TARDIS. (2012).
Left Behind Edit
Shortly after Mardock was left behind, the Death rescued him, and used him to get back at the Beginner. When Jo was kidnapped by the Rock Kind and the Grand Master, Mardock killed her and took her body to the Death, in which he would use her to bait the Beginners into converting her into a Cyberman. Feeling guilty for what he had done, he with Jo killed the Death, causing the conversion chamber to explode, killing the three. (Battle of the Beginner)
Additional Information Edit
Mardock was related to Joanna Johnson. (2012)