He was halfway across St. James’s Square when the full import of his own thoughts hit him, with a force that was almost physical and brought him momentarily to a halt. If “An Ideal Husband” was the kind of thing that pleased the contemporary West End audience, then “Guy Domville,” with its old-fashioned manners and decorous language, its morally fastidious hero and suffering, reticent heroine, its genuine ethical dilemmas and final endorsement of self-sacrifice and renunciation, certainly wasn’t. Although over the last days and hours he had made himself almost ill with anxiety, it was only now that he really believed in the possibility of failure, and he continued on his way at a slower pace, his heart heavy with foreboding.