One William Trevor story that misses, and why

OK, so not every single William Trevor story in "Selected Stories" is suitable for enshrinement in the Pantheon, just most of them. One that falls a notch below the mark, though still an excellent story by almost anyone else's measure, is the late story An Afternoon, about a mid-teen girl who meets a guy through a chat room and arranges a meeting in town, where she finds he's about 30 (at least) - nevertheless she falls for his creepily seductive patter and wanders off with him, gets a bit drunk, heads toward his house where he thinks they'll be alone, till the tryst is broken by his outraged aunt, concerned that he's on probation (for similar assaults) and will go back to jail if the girl rats. Story somewhat less effective than others of Trevor for a few reasons: first, there's virtually no element of discovery or surprise for the reader - we obviously are very aware that the guy (he calls himself Clive) is a predator, and our only wonder is how far he will get in his scheme. Second, though many Trevor stories are dark, few are as seamy as this one - a very unpleasant set of characters. Third, I'm not sure he has such a fine handle on the way a contemporary UK teen speaks or thinks; amazing this 80+ writer can even take it on, but compare with other stories - the next in the collection about an elderly couple forced to sell the farm to a developer, At Olivehill - and you'll see the difference in assuredness of voice. The strength of An Afternoon is, typically, the concluding passage when we see the girl, Jasmin, back at home with her horrible mother and feckless stepfather and we understand for a moment why she so desperately and pathetically seeks what seems to her to be love and attention from an older man.