Suppose that you have a neutral plate whose potential relative to the "ground" is zero.  

As photo-electrons are emitted from the plate, the potential of the plate increases, and so subsequent photo-electrons are attracted to the plate but if they have sufficient kinetic energy they will escape from the plate.  

However, there will come a time when the potential of the plate, $V_{\rm plate}$, is such that the photo-electrons have a maximum kinetic energy, $K_{\rm max}$, which is insufficient for them to escape from the plate, $eV_{\rm plate} > K_{\rm max}$.  

So after escaping the photo-electrons will be "dragged" back to the plate.