Question
I am doing the Knight's 30 quest and I am with Jim. Jim responds with question marks. Is this normal, did I miss something? I have the revival potion.
Answer
Check you have completed all elements of the quest, and spoken to the relevant NPCs.
In particularly, make sure you have completed the Level 15 quest.

It's been quite long time
It's been quite long time for me to do this last time, but it used to be so, that you had to be in skeleton polymorph before Jim spoke to you. Actually you had to polymorph, then restart for Jim to speak to you, but I believe you do not have to do the restarting anymore as that part of polymorphing function has been fixed for years.
So polymorph into skeleton and you might have better luck. Hopefully this helps :)
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Have fun, but let others have too :)