The mischievous teen sets up a practical joke for the Deputy Head, but unable to stand by and watch him walk into the trap, Finn leaps into Rob's path and instead it's the Head who ends up on the floor covered in water.
While Sinead reprimands Finn, they are both disgusted to hear that Amber has a crush on Rob and Finn makes a startling revelation - Rob's their dad!
Meanwhile, Alistair hurries a reluctant Cindy to sign on the dotted line of their prenuptial agreement - he's keen to make a start with the wedding arrangements. But while Cindy philosophises about the brevity of life, Alistair collapses to the floor with an apparent heart attack.
Elsewhere, Rob is promoted to Acting Head and offers Eva a job of design assistant at the school; Steph is shocked by Gilly's denial of the facts and tells him firmly that he has to accept the reality of her illness or else she can't marry him; and Anita is incensed by Eva's stunt and says that she never wants to see her again.