As Sacha continues to put Zosia, Arthur and Dominic through a punishing teaching schedule, Arthur begins to feel resentful of his new teacher. Dominic, meanwhile, would like nothing better than to take Arthur down a peg or two and impress Sacha in the process. When the two are assigned to the same case, the competition heats up. But when things take a turn for the worse, which young doctor will triumph? Serena is furious when she is sent to cover AAU, but a patient presents her with a business opportunity which may help Serena prove her worth to Guy. With her eye on the prize, will she heed Harry's warning that this particular patient is not all he seems? As Jac moves forward with her plans for Emma, Jonny is determined not to be left behind. With help from a familiar face, will Jonny be able to make his wishes heard?