S5·E9 Episode 9

Lorcan's sister Alice, who's back using drugs again, begs Lorcan to help her go 'cold turkey'. Although Lorcan knows it's ethically inadvisable to treat his own sister, he reluctantly agrees to help Alice - on condition that she be locked in the flat. No-one at The Clinic can find out what they are up to. Lorcan is so preoccupied with keeping the whole thing quite that he prescribes the wrong medication to a patient with almost disastrous results, not to mention what happens when Alice collapses at the reception desk.