john 18:16 But Peter stood at the door without. Then went out that other disciple, which was known unto the high priest, and spake unto her that kept the door, and brought in Peter. - Free Bible Online

      16. But Peter stood at the door without--by preconcerted arrangement with his friend till he should get access for him.
      Then went out that other . . . and spake to her that kept the door, and brought in Peter--The naturalness of these small details is not unworthy of notice. This other disciple first made good his own entrance on the score of acquaintance with the high priest; this secured, he goes forth again, now as a privileged person, to make interest for Peter's admission. But thus our poor disciple is in the coils of the serpent. The next steps will best be seen by inverting Joh 18:17 and Joh 18:18.

JFB.