Did Surratt and Slater know about Harney's Mission?

[SSlater]

This is a crucial question. It could change our thinking - drastically.

If they did know, or didn't know, they were not involved in Lincoln's assassination,

Up until 1 April '65, the common goal was to abduct Lincoln. We all know that.

Then, on 1 April, Surratt and Slater left Richmond for Montreal. They were pretty much "out of touch" with headquarters. Next they departed from Montreal, for Elmira. If Montreal knew about Harney, then Surratt and Slater, were not involved and didn't need to know.

Also, on 1 April, Harney left Richmond for Mosby with his own set of orders. All went well until the 10th and Harney is captured.

Somewhere after the 10th, Booth went to New York (for Orders?) Upon his return, he wired Surratt "to Come here - immediately, the plan has changed." (No known reply). Later, Surratt learned of the assassination, but dallied in Elmira, and arrived back in Montreal on the 18th. (Booth had tried to rally his squad, for the new plan, but they balked. (( I'm beginning to understand their thinking)) Murder was not in their thinking)

Did Booth involve Mary Surratt, Dr. Mudd and the Secret Line - in the murder, after the fact?

Surratt and Slater never knew that there was to be an assassination - until it was a done-deal.

What are your thoughts on this?