I DM'd a short Pathfinder campaign I wrote. At one point, a townsfolk's wife was kidnapped while the PC's were out investigating an ogre cave. They tracked the kidnappers to a huge church to Asmodeus and sneaked inside. After a while they found her, but she was being treated as a guest of honour as the church considered her a reincarnation of one of their saints.
The party fled as guards closed in, and regrouped to crash a ceremony to be held later that day. They fought through a horde of worshipers, were smacked around by the high priest, blinded and set on fire. It was a fun fight. Most importantly, though, they failed to rescue the wife in time.
A fully grown teifling clawed its way out of her, killing the wife, before collapsing from exhaustion. The priest was defeated at this point, so one of the PC's who weren't stumbling around blind or putting their selves out stepped up to the alter to kill the helpless creature.
Then he found out it was female and he changed his tune. (Exactly as planned)
When the teifling woke up, she seemed nice so they brought her back to their town and said mission accomplished. Then she raised the entire graveyard and disappeared into the woods.
<----Pictured: a face you can trust.