It is a famous combo in Legacy when Mirrodin comes out. There are only two cards in this combo, one is Goblin Charbelcher, and another one is Mana Severance. The idea of this combo is simple, use Mana Severance remove all lands from your library, then use Goblin Charbelcher kill your opponent. Accoding to rule of mtg, if there is no land your library, the activated ability of Goblin Charbelcher will stop by force when the last card of your library is revealed, and Goblin Charbelcher will deal damage equal to the number of cards in your library. Usually it is the kill.

Notice the Mana Severace is a socery and Goblin Charbelcher is an artifact, which means this combo is easy to search from your library if you use the pure blue deck, Arcum Dagsson for example. You can use something like Mystical Tutor or Personal Tutor to find Mana Severance out and use Arcum Dagsson or Fabricate to search Goblin Charbelcher to complete the combo. That how it works in my Arcum Dagsson deck.