Fblthp, Lost on the Range

If an instant or a card with flash is plotted this way, you can still cast it only when you have priority during your main phase while the stack is empty.

While you control Fblthp, you can look at the top card of your library whenever you want (with one restriction; see below), even if you don't have priority. This action doesn't use the stack. Knowing what that card is becomes part of the information you have access to, just like you can look at the cards in your hand.

If a plotted card has X generic mana in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.