With the KC knocked out, it looks like any time E loses the lead, he will also have to give away another 3xC tricks, limiting him to 9 tricks. However, as the cards lie, E can make 10 tricks by immediately giving up a club and hoping the defenders cash their 3xC. When S cashes his third club trick (the 4th club played), N is under pressure. He can avoid giving anything away for the moment by throwing a D but when E cashes 3xD, N will have to find 2 discards, which he cannot safely do.