A woman has broken your car?
Yes, Mrs TMRBB. She borrowed it yesterday and didn't close the passenger door properly. When it is not shut properly, it will not lock using the remote. Rather than thinking "Oh, there must be a door not properly shut", she assumed the remote wasn't working (despite me putting a new battery in it only a month ago) and locked it with the key.
Result: Interior light stays on and now the battery is flat. We are meant to be heading off for Swindon now.