Eighty-four-year-old Paula is referred to St Georges for urgent treatment, after a routine blood test detected that she has a dangerously high level of potassium in her blood. Meanwhile, 74-year-old Derek is brought into A&E after suffering a suspected stroke. As he goes for emergency surgery, his devoted wife Mary is determined to help him recover. Plus, 31-year-old fireman Glenn arrives with a suspected abscess in his throat; he is joined by his twin brother Dean and the pair are inseparable.