Returning from the theatre with the family one bitterly cold night, Alyce and Emily discover a tramp asleep under a railway bridge.
The next day, the girls feel impelled to search him out in wintry London, and from then on Benedict O'Hara becomes their worry and concern.
Does he really want to return to his native Ireland for Christmas?
And, anyway, could the fare be raised in such a short time?
However, for Alyce there is the more disturbing, though irrational, fear that their marvellous traditional family Christmas might be altogether ruined.