S4, E2: Lewis and Hathaway are called to the Oxford University Observatory where the body of Andrew Crompton, amateur stargazer and Master of Gresham College, has been found at the foot of the stairs. Dr Hobson reveals that she had attended Gresham College the previous evening for an orchestra rehearsal. When a notebook is found near the body, Lewis and Hathaway visit Crompton's wife Isobel who points them in the direction of Gwen Raeburn, senior lecturer in Astrophysics, and wife of the head of Hobson's orchestra, Sir Arnold Raeburn.