If I might make a suggestion; It is important to make sure that the other cleric that joins them does not feel "tacked on" and that there is a real reason for the PC to have been kidnapped.
Given that, I suggest the following:
- The other NPC is in town, possibly the same religion as the PC cleric. When talking to him, he is nervious and suspicious even of other clergy. He is a very worried man.
- A good religion/history role reveals that he is of an order that guards a hidden sacred <insert X here>. It is hard to tell, very subtle heraldic signs on his robes.
- The evil doers can't tell the clerics apart. The PC is kidnapped in a case of mistaken identity. After all, what were the chances that there would be two clerics of apparently the same order, of the same race, in the same town at the same time.
- The PC is kidnapped and interregated about the location of the <insert X here> Despite the torment, he has no idea what they are talking about so cannot answer them. In frustration, they turn him undead in order to be able to compel answers from him.
This has a few advantages:
1) The PC knows why they were captured
2) It does not have to be shoehorned into a wider plot
3) You now have a cleric with every reason to help you, including using the expensive Raise Dead ritual required to save the PC
4) The villians desire to take what the NPC knows is a good plot hook for later. PCs can help protect him, take the artifact, steal it for themselves etc.
Just some thoughts, hope it helps.
<Edit> On a side note, I do not take any garbage from my players about never leaving the party, or being armored all the time etc. If they try that on, I give them a -2 or more charisma penalty, as they are obviously socially inept, incapable of friendships and interests outside of adventuring.
Another suggestion is, have a lady play on his good hearted nature. She runs in barrelling up the priest saying that her sister is having a bad birth and she and her baby might die. He goes to help, the priest gets jumped by the baddies. It is the wrong priest of course, but they don't know that. This gives the PCs a lead to try and track down the cult. They find that the priest left with Trixy the Wench, they track her down, she was paid to lure him outside, but did not know why. She never saw the guy that hired her properly, but he did smell of tar/whatever. PCs can then investigate the cooper/shipwrights/whatever...
In my style of GMing, if the player acts out of character and does not have their otherwise goody-two-shoes character help the terrified lady...it was not a trick and the mother-to-be dies. They are less likely to ignore damsels in distress next time.
