There are movies you know will get sequels. There are movies you expect will get sequels. There are movies you wonder might get sequels.
Then there's "Trainspotting."
Danny Boyle's heroin-not-so-chic, young-Scots-adrift tale was a classic in 1996, at once exoticizing and sympathizing with its working-class heroes. Based on Irvine Welsh's 1993 book, it was so singularly of its time — so singularly of its director's time (Boyle's second film, before anything Hollywood) — that returning to it seems less a head-scratcher than an impossibility.
But Welsh in fact did just that himself, publishing the follow-up "Porno" in 2002. The...