A psycho-killer rides N.Y.'s subways--in a relatively subdued but thinly contrived murder/manhunt thriller. The psycho is young street-beggar Linus Bean, who, for the murkiest clinical reasons (something to do with his foster-home background), roams the crowded subways, occasionally sticking a stiletto into a stranger, and leaving a ""Monopoly"" game-card near the body (a clue to the location of the next killing). His pursuer is transit sleuth Martin Malloy, a divorced, 40-ish ex-cop forced into early NYPD retirement by gun wounds from a hood. And so Campbell alternates predictably between Linus on the prowl and Malloy on the case, with a couple of cornily arranged path-crossings: when Linus is slashed in a scuffle with one of his victims, he takes this infected wound (ineptly stitched up by a bag-lady pal) to Bellevue, where the nurse on duty just happens to be Malloy's girlfriend Irma; and when there's a subway accident right after one of Linus' killings, he and Malloy wind up saving lives together. Soon, then, Malloy is hot on Linus' trail. There's a one-on-one duel in a deserted church (where Malloy expects to meet a Linus crony who's eager to inform on him, now that Linus has killed the beloved bag-lady). Linus escapes and menaces Irma. And finally--the obligatory chase through subway tunnels. ""Derivative"" is putting it kindly, in fact; this is by-the-numbers from start to finish--with little appeal besides the pornography-of-violence, the simpleminded exploitation of urban fears.