Unfortunately Mickey is suppose to join the TARDIS crew.
At least that is what I last heard. Last time I played the Doctor Who PnP game I played a Galifreyan technician who was working on a prototype TARDIS, which malfunctioned and caused me to crash into the Earth back in the 14th century where the other PCs came from. When I finally got the blasted machine to work, which i had to createt he parts from scratch while being in the middle ages, I took the party to 1999 at a Hawaiin Rave. It seemed that the Rave culture was getting infiltrated by an alien race who was using the Ravers as guinea pigs nanite based drugs and sensory enhancers.
It was a fairly wierd campaign