Breaking a leg

[Laurie Verge]

I'm going to get myself in trouble with Jerry again, but if Booth and Herold had passes signed by VP Johnson, they could have exited the city any way they wanted. Why the bridge into Southern Maryland if they did not intend to use the services of the Secret Line in that area?

I did read your book, but I forget the line of reasoning as to why they headed south if they intended to go north. That part of the plan seems to have been thought of ahead of time and did not depend on or change because of a broken leg.