The scene, I assume is this one: https://www.youtube.com/watch?v=YUjPBtlhBls The conversation goes like this:

> **Varys**: He's found one bastard already. He has the book. The rest will
> come.<br> **Illyrio Mopatis**: And when he knows the truth, what will he
> do?<br> **Varys**: The gods alone know. The fools tried to kill his son.
> What's worse, they botched it. The wolf and the lion will be at each
> other's throats. We will be at war soon, my friend.<br> **Illyrio
> Mopatis**: What good is war now? We're not ready. If one Hand can die,
> why not a second?<br> **Varys**: This Hand is not the other.<br> **Illyrio
> Mopatis**: We need time. Khal Drogo will not make his move until his son
> is born. You know how these savages are.<br> **Varys**: "Delay," you say.
> "Move fast, " I reply. This is no longer a game for two players.<br>
> **Illyrio Mopatis**: It never was.

The two men are [Varys][1] and [Illyrio Mopatis][2].

They are talking about [Ned][3] finding one of [King Robert's][4] [bastards][5], [Gendry][6], I assume. The book is the book that the murdered [Jon Arryn][7] reportedly was reading when he died, namely [*The Lineages and Histories of the Great Houses of the Seven Kingdoms*][8]. In that book, Ned can later see that in all previous marriages between Lannister and Baratheon, the children have had black hair, whereas all three of [Cersei Lannister's][9] and Robert's children are blond -- a sign that Robert is not the father.

They are talking about that someone tried to kill [Bran][10], but they do not know who ([we know][11] it was [Joffrey][12]). They state that this will soon lead to [Lannister][13] and [Stark][14] clashing, which will lead to war. If Robert had been alive, this would have been very bad for house Lannister. Illyrio suggests killing Ned, but Varys declines, for some reason that we do not really know. Perhaps he likes Ned, or thinks he has some other redeeming value. If indeed (spoiler ADWD)

>! [Aegon VI Targaryen][15] 

is the real deal, they might have some use of Ned, because he knew some of the people involved, which could support this person.

Of course, we know about [Khal Drogo][16] and [Daenerys][17], and [Viserys'][18] plan to use Drogo's huge khalasar to invade Westeros. (My overly detailed analysis of their game plan is [here][19]. TL;DR: Viserys was being set up as a badguy.) It is interesting to note that they are not talking about Dany here, it is assumed later on that she was not originally part of their plan. 

The rest of the conversation is vague. Perhaps the "two players" refer to Varys and Illyrio, or perhaps it refers to two factions, and this implies that a third faction (or more) has entered the game. 

The game is, of course, *The Game of Thrones*, the struggle for control over the Iron Throne.


  [1]: http://awoiaf.westeros.org/index.php/Varys
  [2]: http://awoiaf.westeros.org/index.php/Illyrio
  [3]: http://awoiaf.westeros.org/index.php/Ned
  [4]: http://awoiaf.westeros.org/index.php/Robert_Baratheon
  [5]: http://awoiaf.westeros.org/index.php/Robert_Baratheon#Known_bastards
  [6]: http://awoiaf.westeros.org/index.php/Gendry
  [7]: http://awoiaf.westeros.org/index.php/Jon_Arryn
  [8]: http://awoiaf.westeros.org/index.php/The_Lineages_and_Histories_of_the_Great_Houses_of_the_Seven_Kingdoms
  [9]: http://awoiaf.westeros.org/index.php/Cersei_Lannister
  [10]: http://awoiaf.westeros.org/index.php/Bran
  [11]: http://scifi.stackexchange.com/q/4613/2256
  [12]: http://awoiaf.westeros.org/index.php/Joffrey
  [13]: http://awoiaf.westeros.org/index.php/House_Lannister
  [14]: http://awoiaf.westeros.org/index.php/House_Stark
  [15]: http://awoiaf.westeros.org/index.php/Aegon_Targaryen
  [16]: http://awoiaf.westeros.org/index.php/Drogo
  [17]: http://awoiaf.westeros.org/index.php/Daenerys_Targaryen
  [18]: http://awoiaf.westeros.org/index.php/Viserys_Targaryen
  [19]: http://scifi.stackexchange.com/a/63335/2256