Some situations make it impossible to resolve all of the effects of a card’s ability. In this case, you resolve effects from top to bottom, and stop when you cannot resolve an effect. Once you reach an effect that you cannot resolve, you ignore any remaining effects on the card. After that, the game continues as usual.
Example: You play an Alchemist. However, there is only one card in the draw pile, and no cards in the discard pile. You add the remaining single card to your hand, and the Alchemist’s effect ends there.