There is a relatively rare bug in the download version of the game where certain friendly NPCs can be hostile. There is a way to alter their alignment, though. See PitBrat's reply in the topic
Help, the imps hate me!!.
If you don't have a save before killing the imp in the inn (or that was awhile ago), you will also need to check out the topic
Reviving dead NPCs.
Alternately, you should be able to get into the bee/wasp garden, where the imp in the inn would have teleporter you, using the topic below. The imp there may also be hostile, requiring the fix above (preferably before getting close enough to initiate an attack).
Teleporting Anywhere, via hex editorCheck your messages (click 'My Stuff' in the top menu bar, then 'My Messages').
