Cheapest priced copy (Shadowmoor): $3.99 at Card Kingdom, near mint, their price list as of .
Dire Undercurrents 
Enchantment · Rare · Shadowmoor · #159
Whenever a blue creature you control enters, you may have target player draw a card.
Whenever a black creature you control enters, you may have target player discard a card.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $3.99 to $14.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Shadowmoor | 159 | Rare | $3.99 | $14.99 |
| Secret Lair Drop | 1578 | Rare | $4.99 | — |
| Secret Lair Drop | 1578★ | Rare | — | $4.49 |
One ruling from Wizards of the Coast
- 1 May 2008An object that’s both of the listed colors will cause both abilities to trigger. You can put them on the stack in either order.