Downing Street insists that the change David Cameron is looking for is so significant it will require a change in the EU treaty, in other words a change in how this whole club works.
Many of the other leaders here simply hate that idea, it's a very long, a very complex process.
In fact, it's a process that won't be complete by Mr Cameron's own deadline of having a referendum in 2017.
That means, you're highly likely to be voting on whether Britain should stay or leave the European Union based on the promise of change rather than actual change itself.
Mr Cameron will be up on the eighth floor of the European Council today, he'll get the floor at the end of the dinner.
It's the first time he's met all of the 27 member state leaders at the same time although he has got round to all of them individually since the election which in itself is quite an achievement.
It marks the next stage of this process, the technical stage.
But the word here tonight is they won't have anything further to discuss, no plan on the table, until December.