Dd(9) is very interested in playing spies particularly secret codes. I thought it would be nice to put together a spy kit for Christmas but there is so much out there. Anyone got any recommendations of what to include. So far I have uv pen invisible ink thing. Was thinking some kind of finger print thing- can you get stuff to dust for finger prints like the police do?? Maybe binoculars/night vision, walking talkies- I saw some watch ones on amazon that looked ok but not great reviews so any tried and tested recommendations welcome. Any more ideas I'm missing? Thanks