A 15-year-old Cook, alone in Crookes' house with Crookes' friends and family as witnesses, was said to have materialized the spirit of Katie King, who walked about, talked, allowed herself to be weighed and measured, and even held the family's baby (Doyle 1926: volume 1, 241).
The final appearances of Katie King in connection with Florence Cook took place in April and May 1874 at the Cook family home in Hackney.