 Roger is back on AAU but his immune system is dangerously low due to his HIV. His son, Zak, also returns and after a few home truths from his dad, he makes peace with him but Roger dies leaving Zak devastated. Elsewhere, Tricia finds out that Mark plans for them to get married today, and she s not pleased when she learns he organised the wedding because she is about to "kick the bucket". After talking to Roger s son Zak, Tricia realises she s not ready to give up and she and Mark finally tie the knot. Meanwhile, patients on AAU are having adverse reactions to drugs, resulting in Matt questioning Donna s competance again. After Reg carries out tests in his lab, it is discovered that the hospital drug supply, organised by Bradley, is full of faulty pills.