Booth arranged with Dr. S. A. Mudd to come to Washington to introduce him to Surratt, which he did on the 23d day of December, 1864. Their acquaintanceship ripened into the closest intimacy with a rapidity that was due to a common sympathy and a common purpose. They were from that time much together, and Booth at once became a frequent and constant visitor at the house of Mrs. Surratt.[8] From this time on the evidence begins to accumulate, showing her to be informed of the work in which they were engaged, and to have fully entered into their scheme as a helper.[9] There were a number of boarders in her house. These merely received the ordinary civilities of personal intercourse from Booth; but with John and his mother his intercourse was always of a private and confidential character. Booth's habit was to come into that house, and after the common-place civilities to tap John on the shoulder and ask him to spare him a moment of his time, when they would retire to an upstairs room and remain in conference sometimes for two or three hours. In John's absence (and he was frequently away) Booth would ask Mrs. Surratt to grant him a private interview, which she always did. What business could this man, who had been so recently introduced to the family, have had that required so much and such strict privacy? Whatever it was, Mrs. Surratt was trusted by him equally with her son. We have now presented the state of things in that house between these parties as shown by undisputed testimony, and will proceed to show from the further evidence in the case what the business was that they had on hand.