Mind's Desire [Duel Decks: Mind vs. Might] Angel but knowledge is a skeleton

but knowledge is a skeleton key

Set: Seventh Edition Type: Sorcery Rarity: Rare Cost: {2}{U}{U}{U} Look at the top seven cards of your library

When Chromeshell Crab is turned face up

Set: Eighth Edition Type: Enchantment — Aura Rarity: Uncommon Cost: {U} Enchant creature

Mind's Desire [Duel Decks: Mind vs. Might] Angel but knowledge is a skeletonSet: Duel Decks: Mind vs. Might Type: Sorcery Rarity: Rare Cost: {4}{U}{U} Shuffle your library. Then exile the top card of your library. Until end of turn, you may play that card without paying its mana cost. Storm (When you cast this spell, copy it for each spell cast before it this turn.)