> Spoilers for "Return of the King" follow, but if I'm capable of spoiling a 50-year-old book for you, well...
>
> > If there is one thing we learn from movies and literature it is that you can be sure that an act of mercy will come back and bite you on the arse.
> >
> > Gandalf and Frodo allow Gollum to live.
>
> But doesn't Gollum's living, you know, save the free people of Middle Earth? If he didn't show up at Mt. Doom, would Frodo have ditched The Ring?
>
> Stephen

Both the examples from LotR end up justifying mercy. Gollum's actions at Mt Doom end up forcing the destruction of the ring *and* prevent Frodo from turning to evil. Also, Wormtongue kills Saruman when nobody else is able to do it. I got the impression, in the book, that Wormtongue's slavery to Saruman was what eventually sent him over the edge and gave him the sheer viciousness and hatred to kill Saruman, when everybody else was still capable of being swayed by the wizard's persuasiveness.

In both cases, all the loose ends are tidied up nicely. You get the happy ending, mercy is shown to be justified, and it even removes the need for the good guys to do their own dirty work.

Brunnen-"getting the bad guys to kill each other or themselves is so much tidier"G