Assassination Trivia

[RJNorton]

That is wonderful, Reignette, and Bill, that is a great guess.

I really cannot think of any hints for this as I do not think the book is very well known. So I'll just give the answer: it's Charles Higham's Murdering Mr. Lincoln. Not only does Higham write that the stable fire was intended as an assassination attempt on Lincoln, but also that Patterson McGee, the prime suspect in the fire, departed the United States on the exact same ship as John Surratt (the Peruvian). Just a coincidence? Who knows.