(A long time ago, on a distant planet.)

[Execution place]

RAFANDO: Death is an increasing problem. With over a billion intelligent species active in this galaxy alone, it is an ever-greater challenge to know how to kill all of them. On this planet, we are proud to serve as executioners to every living thing. The destruction of a Time Lord, however, is a particular honour.

(The Doctor is escorted to a dais by a lakeside, outside a castle. It has a copper ball topped column at each corner.)

RAFANDO: This technology is precisely calibrated. As you can see, it will stop both hearts, all three brain stems, and deliver a cellular shock wave that will permanently disable regenerative ability.
DOCTOR: I know how it works.
RAFANDO: You certainly will in a moment. Following termination, the body will be placed in a Quantum Fold chamber, under constant guard for no less than a thousand years. In case of, shall we say, relapses. Life can be a cunning enemy. An additional stipulation of the Fatality Index is that the sentence must be carried out by another Time Lord. Apologies for our choice, but your people are not easy to come by.