Epic Experiment (C15) from Commander 2015, available at 401 Games Canada.

• Rarity: Mythic Rare
• Finish: Normal
• Artist: Dan Murayama Scott
• Card Text:
  Exile the top X cards of your library. For each instant and sorcery card with converted mana cost X or less among them, you may cast that card without paying its mana cost. Then put all cards exiled this way that weren't cast into your graveyard.