A familiar face returns to restore order at Waterloo Road and protect a student in trouble. As the walls close in, can Steve and Billy protect their secrets, or will they be found out? Meanwhile, Nicky and Donte's relationship is put to the test after being pulled in different directions. Will they manage to stay together, or will they be broken apart? Elsewhere, facing a big decision about his future, Preston is shocked by a surprise visit from some old friends.