They have spent the last two days doing the same one. And the last two nights doing the other 19.
One of the ads is for the National Power/Powergen sale of remaining shares. "An impressive release of power" it says, over a volcanic eruption, all red and black speckly bits that are absolutely indistingishable. On the back of that is "Share the power" a clever tie-in from the Billericay who are a share shop for the offer. It's all red and black too.
In his dream, it's bloody cold on the scaffolding, and he keeps dropping the slats. They fall and impale passersby.
Then Nick Berry, Britain's highest paid television actor, steps in, dressed as a bobby. He starts passing Henry the slats in the right order, and Henry sees that yes, for real, this is the right order.
Then someone shouts "Everybody!" With a snort he wakes.
The right order scatters.