Or should I give up?
It was rolled up in our dining room under the radiator for about 5 days (I'd rolled it back so the kids didn't get food on it near the table, and just hadn't bothered to roll it back again). One of them must have spilt loads of water on it, because when I unrolled it it was all wet on one side with fluffy mould growing on it. (I thought the place smelled a bit funny...)
Is it worth trying to rescue it, or should I just give up and throw it out?