The hon. Lady is absolutely right that the rise in serious violence in our prisons is wholly unacceptable. It is pretty clear to me that the biggest cause of that change has been the presence of so-called legal highs—new psychoactive substances—in our prisons. Only last Friday, I spoke to a prison governor who said that it is the key problem that staff face. We have taken a number of steps, including criminalising the throwing of substances over a wall in prisons. We are about to trial body scanners in our prisons. We will take all steps that we sensibly can to protect our staff. These substances are a danger to our society as a whole. They need to be dealt with effectively in our prisons, and they will be.