john_amend_all

Hang on. You've got a wormhole which will admit anything metal, or shielded by metal. You've got two-way communication across the wormhole. So attach one end of a steel cable to a remote-controlled bomb disposal vehicle, send it through the wormhole, tie the cable to the bus, and drag it back. Episode over in ~15 minutes, with no funny-looking CGI.

And despite my use of the 'Fridge logic' tag, I didn't think of this afterwards. I thought of it pretty much as soon as the bus driver got zapped.

And while it may be a nice heartwarming ending for the kiddies that Lady Christina gets away scot free, I suspect that the moment the Doctor's back is turned, UNIT are going to have every helicopter they've got chasing that bus for its antigravs. If she's lucky she gets forced down and arrested. If she's unlucky or cocky she's blown out of the sky.

ETA: And why would they run out of diesel when they couldn't get the engine to fire? More likely that they'd run the battery down frobbing the starter motor. But, again, it shouldn't be impossible to get more diesel or more batteries through the wormhole from London. I see the thumb of the author on the scales here: "There will be a flying bus in this story, whatever it takes!"