There was no bus service.
The roads were closed.
The head said that if it was too difficult to get there, not to worry - although they did _think_ they'd be open.
But a bunch of small people were expecting a lesson on animation, which wouldn't happen without me being there.
Sustrans-ing it, the long way, was the _sensible_ alternative. Which meant that it took so long to get there and back (plus we overran the lesson because we were having fun) that instead of finishing work around 6 it was after 8, even without stopping for lunch, or indeed breakfast.
Mind, we got the lyrics and storyboarding all done. And I reckon that it wasn't a bad lesson at all.