Ash front moving east: filters mandatory above ground

Since the second the western sky has been the colour of a bruise. The Continuance has been burning off the Midlands farm belt to 'restore soil continuity', and the ash is coming east on the prevailing wind. At 16:00 on the third it crossed the Sector 11 boundary at Edgware: a brown wall three hundred metres high, moving at walking pace.

The column

Ahead of it came the people. Roughly six hundred from the belt villages, walking the old A5 with everything they owned on their backs and in prams. Every one of them was masked, in whatever they had: army surplus, fire brigade issue, painters' half masks, a child in a cut-down riot mask with the visor taped up.

They walked eleven kilometres to the Kilburn tunnels without stopping, because stopping means breathing more. Nobody filed for travel. The Bureau posted a notice at Edgware reminding them that unfiled relocation is a care infringement. Someone had drawn a moustache on it in ash.

You don't hear the ash coming. You taste it first, like pencils. Then you can't see your hand. (A woman from Radlett, carrying twins)

Filter orders

• Masks on above ground at all times. Change filters every eight hours, and keep a wet folded cloth as backup. Filters are with the Quartermaster; do not pay market prices for them.
• Seal hatches with wet sacking. Relay crews, bag your valve sets in waxed cloth. Ash kills valves faster than it kills people, and we cannot grow new valves.

One more thing. Kestrels cannot see through ash either. For as long as the front sits over us, we have more sky than we have had all year. Use it. And make room in the Kilburn tunnels. They walked eleven kilometres. The least we can do is shift up.