As of 25 December 2015, a total of 826 episodes of Doctor Who (BBC, UK) had been aired. This total encompasses a full-length TV movie but does not include spoofs, spin-offs or webisodes. The 12th incarnation of the Doctor is played by Peter Capaldi (UK). Up until 2015, he had been assisted by Clara Oswald (Jenna Coleman), but in 2016 he is due to get a new companion called Bill (Pearl Mackie).
A story arc (or story line) can be anything from one to 10 episodes long; the TV movie is the 1996 UK/US production that premiered on Canadian TV on 12 May 1996 with Paul McGann and Sylvester McCoy as the Doctors.