[felixosmosis]

Hi everyone.  I am planning a murder mystery dinner/play, and the weapon is poison.  The murderer poisons the victim during dinner, and the victim dies about an hour later.  What kind of poisons could have this kind of delayed effect?

The murderer is a college student majoring in chemical engineering, so they've taken a lot of chemistry classes and could have access to chemicals used in lab.  If there is some kind of poison they could make up using household objects, that would work as well.  A lot of what I've found online is plants/mushrooms, but we need it to be some kind of chemical so it will link back to this student.  I also read a little bit about cyanide, but it sounds like it would work too fast.  After the dinner, the person needs to be walking home, he will get attacked by an enemy, and then soon die afterwards so that it looks like the enemy killed him (until the autopsy is revealed).

Now that I've reread that, it sounds really creepy, but I promise it's for a play!!

I apologize if this is in the wrong forum, but the murderer is taking Organic II with lab, so I figured I'd start here. Thanks for your time!