midnight
Contrary to custom , Pierre went out first . A few minutes afterward , Paul left , starting in an opposite direction from that taken by his father . Puzzled at this change in Lanier habits , and fearing some new flight , the assistant followed , but soon losing sight of Paul , returned to watch that cellar stairway . `` After midnight , Paul came back . Limping around the corner , faint and exhausted , hours later , Pierre staggered down the stairs . `` We were then sure this spy was Pierre Lanier , who for the first time had witnessed Paul 's Thames infatuation . This was confirmed later by Pierre 's limping walk .