The Chase was the title of a 1965 episode that tends to be regarded as one of the SILLIEST and most unlikely of all the early episodes, and included a downright silly scene at the top of the Empire State Building, an even sillier one on the Marie Celeste, and degenerated completely in the haunted house of Dracula and the Frankenstein monster. The basic plot was the Daleks pursuing the TARDIS through time and space.

This story takes up a similar idea, but in a much more plausible way. It begins with Wyn’s 18th birthday treat, a trip up the Empire State Building. I’ve never been, and I don’t want to, judging by the details on the official site. The time it takes to queue up, be checked by security, checked again, queue again for the lifts makes it a horrendous way to spend a day out. Going with The Doctor to cut through the red tape is the only way!

But anyway, it made a starting point for the story that tied in with the old Chase, before going off in its own direction as The Doctor fits the randomiser to the console and they take a mystery tour until, finally, they end up coming back on The Doctor’s life. They find the TARDIS as it was when The Doctor and Susan first left Gallifrey and travelled together. The Doctor meets his granddaughter as a young girl of twelve who, nevertheless, defends the TARDIS from the intruders until she realises they ARE friends. The Doctor then has to protect her and his earlier incarnation from the alien that is pursuing them in order to prevent his life from being unravelled and a huge paradox ensuing.

This time he doesn’t kill. He finds another way to keep the alien from being a nuisance to him or to anyone else, fixing the randomiser to the alien’s spaceship and telling him that there is a bomb incorporated in it that will kill him if he tampers with it.

The idea that the TARDIS might have had a homing device put on it many centuries ago that remained undetected is stretching things a little, but not as much as the original Chase stretched it by telling us that the crew and passengers of the Marie Celeste chose to drown themselves rather than face the Daleks.