Where's the TARDIS?
I'm afraid this isn't up to The Doctor.
I'm always wary of time travel shows. Larry Niven was quoted as saying "I would jump in the machine and go back and kill the inventor. And then not be able to go back and so on".
They did cover the grandfather paradox and the no bump rule but then go and violate them.
The thing with time travel is that things that are going to happen have already happened and you can't go back and fix something that's "not broken".
I hate time travel. Picking on Niven again, read his "All the Myriad Ways" for the only way for time travel to work.
I'm giving it a meh. It gets two more shows but I have a bad feeling about it.