How do you rip a heart out of a human's chest? And make it look convincing on camera? Those are the questions we're facing in the last hour of an extended day's shoot (12 hours on set instead of 11). We've shot two big scenes today, both in the same space -- we call it the green corridor -- and now we're aiming to get a third. 'When shall we three meet again?' The nurse-witches have the recently dead 'bloody sergeant' on a hospital gurney. They mattter-of-factly run through their first incantation, before the third of them reaches across the prone corpse, plunges her arm into its chest and brings forth the strikingly convincing object to be seen above.

'Let's do it while the blood's still fresh.' Director Rupert Goold urges on the crew as we have less than a half hour to get these final shots of the day. Hywel John is laid out on the trolley with a major head trauma and a prosthetic bone poking through the skin of his leg. He's drenched in blood, much of which has dried and caked on his body throughout the day. And of course the make-up team need to apply more.

I'd never really thought about this before but the make-up, costume and art departments each work with different kinds of fake blood. (The heart is fake too, in case you were wondering.) For costume, the key issue is whether it will wash out or not, whereas make-up are much more concerned about getting a deep, dark colour. Apparently there's one man who mixes just the right kind of blood for them, and he's their current favoured supplier.

The witches try out various ways of wrenching the heart from Hywel's chest. These look more and less convincing on the camera monitor. Rupert would like to film the scene in a single shot but it's quickly clear that we can't make it like this. So we break the scene into three with a close-up of the heart coming out of Hywel's blood-drenched dressing -- a moment that will probably be almost submiminal in the final cut. It looks pretty scary as we shoot it -- and hopefully, edited and graded and with a powerful sound track it will be scarier still by the time you get to see it.

This morning we shot the scene in which Macbeth learns that his wife is dead. This is Kate Fleetwood's first day on set -- and 'all' she has to do is to play dead throughout the scene. It's a complex set-up and everything takes a long-ish time to set, but Patrick is able to pull off a masterly performance of 'tomorrow, and tomorrow, and tomorrow'. Over lunch the green corridor is re-dressed as a field hospital for the the film's first scene in which the bloody sergeant informs Malcolm and Duncan of the battlefield victory of Macbeth and Banquo.

We keep up a driven pace through the day but even so we have to go ten minutes over the allotted stop time. Which is not a good practice, and we have to get better at our production pacing. Each night, as we have just now, we review the schedule of the days to come, re-working the placing and shooting order of scenes, trying to make the most of each minute that we have on set. It's tricky, and despite the best efforts of everyone you never quite get it right.

That said, some of us over the weekend have watched the first assemblies of the scenes we filmed early last week. There's a lot of work to do but it's exciting to see the film beginning to emerge. These first assemblies are always hard to watch -- the director, the DOP, the producers have all been expecting so much in the abstract and now they are faced with something concrete and real. Which can be a little disappointing and dispiriting. But not, it's fair to say, this time. We're excited -- and keen to move on to the next scenes tomorrow, when we go for the first time into the elaborate kitchen set that our art department have built at the location. Tomorrow, and tomorrow...