Emrakul and graveyard removal

[(nameless one)]

Here is the scenario:

I have assembled the Grindstone+Painter's Servant combo. I have enough mana to mill my opponent's library. Halfway milling my opponent's library, Emrakul, the Aeons Torn was milled. Can I use a graveyard removal such as Tormod's Crypt to remove Emrakul and the rest of my opponent's graveyard before Emrakul's graveyard clause triggers?

If yes, would Grindstone keep on milling my opponent's library or would I need to reactivate Grindstone to finish the job?

Thanks

[Meekrab]

Nobody gets priority until Grindstone's effect finishes. You can then respond to Emrakul's triggered ability however you want.

[Neuad]

or play leyline of the void =p

[(nameless one)]

Nobody gets priority until Grindstone's effect finishes. You can then respond to Emrakul's triggered ability however you want.

So my opponent's entire library gets dumped to the yard before Emrakul's graveyard triggers. Cool thanks.

[jrsthethird]

If it's Progenitus instead, do you shuffle it back when Grindstone finishes resolving, or do you shuffle it in the middle of the Grindstone resolution?

[Meekrab]

If it's Progenitus instead, do you shuffle it back when Grindstone finishes resolving, or do you shuffle it in the middle of the Grindstone resolution?
From here: http://www.wizards.com/magic/magazine/article.aspx?x=judge/article/20090406a


Q. OK, so what happens if an opponent puts a Darksteel Colossus into his graveyard due to Grindstone?

A: Darksteel Colossus is a bit different. It does not have a triggered ability like Gaea's Blessing; its relevant ability is a static ability that generates a replacement effect. Replacement effects do not use the stack; they alter the application of some other action or event. As the Colossus would go to the graveyard from milling, it is instead shuffled back into its owner's library. This cannot be responded to like Gaea's Blessing's ability, as the Colossus' ability alters what happens when Grindstone's ability resolves. Because the Painter's Servant is in play this means that this individual Colossus card can end up being 'milled' over and over again, as it will be returned to the library before the next two cards are milled.

If there is only one Colossus in this library, that means that eventually the only card remaining in this library will be the lone Colossus. This is because the Colossus and some other card would be the last two cards in the library. They would both be milled and the Colossus would be shuffled back in by itself. As the last two cards did share a color due to the Painter's Servant the milling process would be repeated again. This time you'd just mill the Colossus and shuffle it back in. But because the Colossus was the only milled card it did not share a color with another card, so the resolution of the Grindstone's ability will end.

Q. What if the opponent has two copies of Darksteel Colossus in his library?

A: You just had to go there, didn't you? If there are two Colossi in the library, then as the Grindstone ability is resolving they will be milled with other cards and individually shuffled back into this library. Assuming that there are no other effects applied as the Grindstone ability is resolving, eventually the only two cards in the library will be the two Colossi. These two Colossi will then end up being milled, and shuffled back into this library over and over. This will cause this Grindstone ability to loop as it can never completely resolve. Anytime the game enters a mandatory loop that no player can break, then it is a draw. So this game will be over, no one actually won it, and you move on to the next game.

That should pretty much cover Grindstone questions for a while.