Poll - are there any good prequels?

[jack]

This came up in the pub last night with the scifi society -- are there any good prequels, preferably scifi/fantasy? We thought of:

Children's books where the prequal is written second out of a series: Magician's Nephew, Charmed Life.
Series written out of order, such as Hornblower, Small Gods in TP.
Retrospective prequels: Asimov's robot stories became prequels to his foundation novels, though weren't at the time.

I decided that it's because prequels generally get written when an author (or their heirs) runs out of ideas, even more so than sequels, but if that's not the case they're by no means inherantly bad.

Can you think of any others?

Comments

[ptc24.livejournal.com]

OK, Small Gods, pages 215-216. http://www.rot13.com

Gurer'f pyrne rivqrapr bs gur Yvoenevna farnxvat va guebhtu Y-Fcnpr, naq erfphvat obbxf. Ohg vg'f gvzr geniry:

"Orpnhfr vg nzbhagf gb gvzr geniry [...] Ohg vs n yvoenel vf ba sver, naq qbja va gur uvfgbel obbxf nf univat orra ba sver..."

BGBU, VFGE gur Oehgun/Bz "pbafgvghgvbany eryvtvba" onetnva jnf bayl zrnag gb ynfg n uhaqerq lrnef, urapr gur raq. Ohg gura ntnva, gur raq vf nzovthbhf.

[atreic.livejournal.com]

Fair enough. But I still don't feel it's a *prequil* as such. It doesn't explain something that has already been written about, which is what I think the essance of a prequil is... it just happens to be set in the same world at a slightly earlier time.