Agatha Spurrell is an esteemed British climatologist. She is one of Sherlock Holmes' "Irregulars" who he employs when he requires expertise in climate matters. They are also sexual partners.
Sherlock met Agatha when she was consulting for Sherlock's father Morland on a land deal in the Brazilian rainforest. Sherlock was investigating a man who'd thrown his wife from the Splügen Pass in the Swiss Alps. Agatha helped to prove that visibility was good on the day in question and that the wife's death was not the accident that the husband claimed it to be.
|Agatha is in NYC to deliver the keynote speech at a climate conference. Holmes prepares for several days of sex with her while Watson stays at a hotel. The next day, Watson visits the Brownstone and finds that Sherlock is hiding in the basement as Agatha asks him to have a baby with her. Agatha doesn't want Sherlock involved in the child's life. A day later, Watson asks Sherlock about the situation. He's puzzled why Agatha would risk their relationship over the request and doesn't consider himself father material. Sherlock confronts Agatha at her conference and accuses her of making the request to fulfil a bargain with Morland who has funded her research until 2023. She denies this and indicates she asked him because of his many skills and asks him to think about it. Later, Sherlock refuses her request and explains to her that his gifts come at a great cost and he doesn't want to pass this onto someone else. Agatha leaves a day early. ("The View From Olympus")