Flotsam, +Jetsam (2)
Mill three cards. Investigate. (Create a Clue token. It's an artifact with ", Sacrifice this artifact: Draw a card.")
Each opponent mills three cards, then you may cast a spell from each opponent's graveyard without paying its mana cost. If a spell cast this way would be put into a graveyard, exile it instead.
Gatherer works better in the Companion app!