The Scottish Ploy

In The Scottish Ploy, British sleuth Mycroft Holmes and his associates contend once more with the sinister agents of the secret organization known as the Brotherhood.
Seemingly unconnected events pull Mycroft in several directions at once. To prevent the leaders of an anarchist group from reaching England’s shores, Mycroft must, much to his dismay, become part of the intended reconciliation of a husband and wife.
Then there are the minor puzzles: Why is gentleman who claims to be Turkish seeking his supposedly kidnapped brother in London? Why does an eminent phrenologist urgently want Mycroft’s opinion on the inhabitants of his asylum? Who has been following Mycroft and his estimable secretary, the amiable Paterson Guthrie, through London’s foggy streets? What motivated the attempted assassination of an Admiralty courier on Mycroft’s own doorstep? When the lovely Penelope Gatspy saves Guthrie’s life, is it because of the attraction between them or on orders of the mysterious “lodge” she serves?
But, most important to Mycroft—who is behind the kidnapping of his old friend, the actor Edmund Sutton, who was in the midst of a triumphant run as Macbeth in Shakespeare’s infamous “Scottish Play”?