One thing you hear from some families of hostages is that they won't quite believe their loved one is coming home until they are walking through the door.

It's a good indicator of the lack of trust between the two sides, for very obvious reasons.

I was in a briefing with a former Israeli hostage negotiator earlier this week who said that the point in these negotiations is that, of course, there is absolutely no trust between Israel and Hamas. And what you effectively replace that with is a sort of confidence and a respect in the mediator, Qatar, which seems to have worked quite well.

They've got a lot of mechanics worked out - where the Red Cross is going to be, and that Israel will stop its drone surveillance above Gaza for six hours in the run up to the hostage release at 16:00 (the specific timings on the surveillance outage are according to the account of the deal by Hamas).

That’s probably because Hamas thinks Israel would use that intelligence to work out where the other hostages are being held.

Obviously, they are trying to conceal that from the Israelis so it’s possible they wouldn't have signed up to the release agreement if the drone surveillance was there.

Israeli officials have previously said they have “other intelligence gathering capabilities” for when there are no drones and balloons in the air.