Dan and The Doctor (Phanfic)

Dan Howell (AKA danisnotonfire), finds a key one day, in central London whilst walking home from his Saturday job at M&S. Little does he know that this key fits unlocks the most notorious machine ever invented. He has 3 choices, (1) He leaves the key (2) He hands it into the police station (3) He gives in to curiousity and fits it into that neat blue box at the end of his street...