In the case referred to in the last section, where the points of the snag just touch the sides defining the region of the Feature, a crisis occurs and arbitrarily small amounts of noise can eject the system from the Feature. If the points extend beyond the Feature, there will be a probability of escape even though there is no added noise. The motion will then consist of periods of chaos within the Feature, interspersed with intermittently occurring periods of motion outside the Feature. This behaviour we call crisis-induced intermittency. The intermittency sets in suddenly at the crisis point in the case of a hypothetical system with no added noise. However, in a real system with Gaussianly distributed added noise, the crisis point is less well defined as the Feature size is increased.