The security lockdown in Brussels since the Paris attacks has not stopped behind-the-scenes discussion of the UK's agenda for EU reform.
Over the past week officials from the European Council - the EU's top policy body - have held bilateral meetings with representatives from each member state to discuss Prime Minister David Cameron's demands.
I'm told aides of European Council President Donald Tusk went through each area of proposed reform, to establish where compromise could be reached and what would prove more difficult to negotiate, ahead of the UK's planned referendum on EU membership. That stage finished on Monday.
These so-called "confessionals" were a chance for the council to sound out each country's reaction to the letter in which Mr Cameron set out his wish-list for change for the first time.
Few oppose plans to make the EU more competitive and cut back on red tape. And it's thought there is the political will to give the UK some exemption from the idea of "ever closer union" - although exactly how is still to be negotiated.
Free movement worries
When it comes to protecting non-eurozone countries, the devil will be in the detail. Deciding on a mechanism by which this can be achieved could be tricky, but insiders suggest some sort of agreement is likely.
Perhaps unsurprisingly the area that's causing concern is the UK's plan to ban in-work benefits for migrants for four years.
Publicly, some European leaders have already said they wouldn't support anything that could undermine the principle of free movement or lead to direct discrimination against some EU citizens.
Privately, I'm told some of the latest conversations have been even more robust.
A representative from one country said there was acknowledgement from all involved that it was going to be "very, very difficult" to reach a solution.
Some think David Cameron does need to be seen to do battle with his European counterparts, in order to ensure any concessions he wins are seen as worthwhile in the UK. But on this point, it seems the fight might be real.
As a consequence, after the "confessionals" some EU countries think it's highly unlikely that a deal will be reached before a key council meeting in December.
Or as one official put it: "A December deal would be a miracle".
Downing Street has been keen to stress the timetable will be dictated by the substance of the negotiation, so if things aren't resolved by December, they can't be accused of delays.
The UK government will now work out with the European Council how best to proceed; no doubt the calculation over timing will be as much political as practical.
But with the fallout from the Paris attacks still dominating and December fast approaching, David Cameron's hopes of getting a deal on his complete wish-list by then looks increasingly unlikely.