At some point in his life, Horley sold a Charpentier mezzotint to a man who never paid. When the man was confronted by Horley's lawyer, he offered a bronze monkey as payment.
One week later, the bronze monkey arrived in a wooden box. That night, Grinstead visited Horley at his college. They discussed the artworks in the Senior Common Room. Grinstead asked to see them, so Horley invited him up to his lodgings at the college. Grinstead recognised the subject of the portrait as Marisa van Zee, an ex-lover of his, which astounded Horley as the painting was 70 years old, but Grinstead was less than 50. Grinstead told Horley that there were many universes and that time passes differently in different worlds, which Horley found difficult to believe.
Horley began to feel ill; he was itchy, short of breath and he developed a rash. After opening the box which contained the bronze monkey, Horley was violently sick and became unable to breathe. He told Grinstead to phone an ambulance from the Lodge, but Grinstead left him to die. His death was attributed to anaphylactic shock.