There are philosophers who think that it is possible to imagine the metaphysically impossible. On the one hand, there are philosophers that think that only knowledge limits what one can imagine. Prior to knowledge of certain facts the imagination is unbounded. On the other hand, there are philosophers who think that the imagination is unconstrained whatever. I shall argue that (a) it is not actually possible to imagine what is metaphysically impossible, though (b) it appears to be possible. I take this to be a defence of the Kripkean view. I aim to develop an understanding of the imagination that can accommodate this view.