[fowlplay4]

I wrote one that:

1. Opened the level the player was in. (loadlines)
2. Stripped the NPCs out and overwrote my "spy" level. (savelines)
3. Created a bunch of actor NPCs with an account attached to it and joined my actor class that updated the actor's look, x, y, ani, and attrs. (putnpc2, join)
4. The main script would check for new players entering the level and add/remove as necessary.

You're in over your head!