Who do the Special Legion meet with in Chapter 21 of the novel, The A.B.C. Murders?

In Chapter 21, part of the Special Legion group meets Inspector Crome, who has no interest in what the group has to say. Franklin, however, says that they are a strong group and tells Crome about the St. Leger run being run in Doncaster on the same day as the next murder..... something that will make the murderer harder to find.