and black has nothing more than a draw by repetition. note that only the squares c4 and e5 will do for the white knight; if, for example, 4.nd4 then 4...nc2 allows black to free himself (this is not possible with the knight on e5 because of nxd3#); and if, for example, 5.nc6 then black can free himself with 5...rbc1 or 5...rdc1 (not possible with the knight on c4 because of na3# and ne3# respectively).