Two-Two made a thumbs-up sign to her friend, but Niney was attending to the work in hand, overseeing Noughtie's demise .  Two-Two mouthed 'Good-bye', waited a moment, negotiated a careful three-point turn and returned dutifully the door of her own allotted carriage.  Once there, she turned her head for the last time to look at her friend, mouthed 'Good luck', paused, raised her right hand in farewell, held it still a while and then entered her carriage, taking care not to knock the paintwork.