When two people have been as near to death in company as they had been, it can hardly be expected that they will regard each other in the light of total strangers should they chance to meet again.
Hidden from his sight by an intervening yew tree, she watched him coming down the church path, conscious of a somewhat pleasurable sense of anticipation, and when he had passed under the lichgate and, turning to the left, came face to face with her, she bowed and smiled, holding out her hand.
To her utter amazement he looked at her without the faintest sign of recognition on his face, pausing only for the fraction of a second as a man may when some stranger claims his acquaintance by mistake; then with a murmured "Pardon!" he raised his hat slightly and passed on.
Diana's hand dropped slowly to her side.

She felt stunned.

The thing seemed incredible.

Less than a week ago she and this man had travelled companionably together in the train, dined at the same table, and together shared the same dreadful menace which had brought death very close to both of them, and now he passed her by with the cool stare of an utter stranger! If he had knocked her down she would hardly have been more astonished.
Moreover, it was not as though her companionship had been forced upon him in the train; he had deliberately sought it.

Two people can travel side by side without advancing a single hairsbreadth towards acquaintance if they choose.