The Master and The Doctor in “The Sea Devils”

Once they see that the device works properly, they'll release me.

I very much doubt it. You see, before you reactivated it, I reversed the polarity of the neutron flow.

You did what?! You realise what will happen?!

Oh, yes. Do you?

Well, there'll be a massive reverse feedback into their whole power system.

Exactly. In about ten minutes from now, the whole place should go up. Enjoy your revenge.