With Evelyn gone, the Doctor sets course for his destiny... in the form of his first meeting with Miss Melanie Bush, a computer programmer from the village of Pease Pottage, currently busy rehearsing with the local Amateur Dramatic Society - and blissfully unaware that her future is on its way, in his TARDIS.
Make that two TARDISes. Because at that very moment, a slightly younger Doctor is flying into Pease Pottage, too - returning his future companion Melanie Bush to her rightful place and time, after they were flung together during the course of his Time Lord trial.
Time travel is a complicated business - the iguanadon terrorising Pease Pottage being a case in point. But how much more complicated could things possibly become, if the wrong Doctor were to bump into the wrong Mel?