This is one of the more unique 3 Shell Game routines around. It utilizes the Chazpro telepathy card principle. You get three cards with pictures of walnut shells on one side. One card has a green spot (pea) on the under side. Despite how much the spectators are allowed to mix the cards, even while in envelopes, even with the performer's back to the spectator, the performer can always find the pea.

Repeatable.
No set up.
A great challenge trick, that defies explanation.