If you were scratching your head for a minute (or a few) at this week's "Breaking Bad," you weren't alone.
The ricin poison is one of "Breaking Bad's" longest-running dangling carrots, but the history of the ricin -- including why it was made, where and how it has changed hands and what prompted Jesse's semi-confusing realization in "Confession" -- isn't as easy to keep track of.
So we did it for you. Above, watch our mash-up (appropriately titled Where In The World Is The Ricin?) to remember the history of one very evil man and his vial of untraceable deadly poison.
And don't forget that in flash-forwards this season, we've seen future Walt make a special trip home just to unscrew that outlet cover and retrieve his stash of chemical weaponry, making the next logical question: Where in the world might the ricin be used?
Watch our mash-up above for a refresher, then share your theories in the comments!