Re: A thought on regenerations (spoilers for "Night/Day of the Doctor"
We also know that Time Lords can be killed instantly by a Gallifreyan staser bolt as we saw in The Deadly Assassin, we also the Doctor's friend Runcible die of a knife to his back and Goth died of his injuries all before they could regenerate.
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or all in a bunch to back it up!"
--- Harlan Ellison, from his introduction
to the PINNACLE series of Doctor Who books