Jonathan Sims is the current Head Archivist at the Magnus Institute, London. His predecessor was Gertrude Robinson, who recently passed away. He comes from Bournemouth (MAG 3). He has been shown to be dismissive of many of the cases, believing that truly arcane or esoteric reports are few and far between, though events of late are starting to seem worrisome. He has done almost all of the audio recordings for the Magnus Archives. He is helped by Martin, Sasha and Tim, researchers at the Institute, though he seems to hold Martin in particularly low regard, at least until after his reappearance in MAG 22: Colony.
Mr Sims is keen to digitise the Archives; however any attempts to record onto his laptop have caused significant audio distortions, so he has had to settle for recording onto archaic tape recorder.
Following the events of Colony and Jane Prentiss' siege of the Institute, he has become more and more concerned about the dangers of his job, including a sense that he and his co-workers are being hunted.