Spies: in your own cities

[Ulstan]

I've tried to send in assassins to kill enemy spies keeping my spies out, but I have had no luck with that. They don't show up as people to assassinate. How do I get them to appear?

[Spuddicus]

If they have any spies in a city, they should show up in the list of valid targets when select the city with your assassin.
Be careful though, if you have your own spies in there they'll show up as well (accidentally killed a couple of mine this weekend that way).

[Jeanne d'arc]

Some cities i tried to infiltrate had a 9% chanche to succeed, gues they must have had a enemy spy inside it, always thought it was a bug or something.

[therother]

Some cities i tried to infiltrate had a 9% chanche to succeed, gues they must have had a enemy spy inside it, always thought it was a bug or something.

With that low a %, either you have a very poor spy, and/or there are one (or more) good spies in that city! Use an assassin to get rid of them!