I read this fic on Fanfiction.net, but the writer's got a site as well on
http://www.geocties.com/ms_danvers
It's called Bane Of All Mankind and it's an NC-17 Jack/Daniel fic.
I've been reading it for yonks but she still hasn't finished it (it's about ten chapters long already).
Basically on this mission Daniel gets kidnapped by this really sexy Goa'uld who wants him. Sexual danger is what someone wrote in their review on Fanfiction.net. It's pretty good.
I also like JD Divas at
http://www.geekiness.com.jd_divas
They've got some really good fics (especially Biblio).
Nina