In “The Memory of a Killer,” also known as “The Alzheimer Case,” Erik Van Looy has done a nice job of putting together an engaging, high concept thriller. But once we’ve finished being caught up in it, the high concept pretty much goes to waste.

It is this. A professional killer, Angelo Ledda (Jan Decleir) realizes that he’s showing the first signs of Alzheimer’s disease. His brother, Paolo (Roland De Jonghe), has already been institutionalized with the affliction, and Angelo visits him while in Antwerp to do a job. Paolo has no memory of him – or anything else. A nurse asks Angelo if he is a relative.

“Distant,” says Angelo with a touch of black humor we don’t see much of thereafter.

He has been hired by a man named Seynaeve (Gene Bervoets), who is working for Baron Henri Gustave de Haeck (Jo De Meyere). The baron’s ne’er-do-well son, Jean (Tom Van Dyck), has got himself into a spot of bother over a child prostitute, Bieke Cuypers (Laurien van den Broeck), and is being blackmailed by one Bob Van Camp (Lucas van den Eynde).

Angelo successfully retrieves the money and the evidence from Van Camp, who pleads for his life with Angelo’s gun to his head, swearing never to talk. Will Angelo spare him? Is his moment of hesitation here a pang of conscience or another Alzheimer’s moment? We never have the chance to find out, for Bob suddenly decides to fight his way out of Angelo’s grasp – which proves to be a big mistake.

Then, while Angelo is still holding his corpse, the dead man’s daughter calls out from just around the corner, “Daddy?” She makes as if to come and find him, and Angelo is presented with another dilemma. There seems to be nothing to do but kill her, too. Once again, however, Van Looy lets him off the hook. The girl thinks better of coming in search of her father and merely calls out that she will be over at the house of a friend before leaving by another route.

These are dim foreshadowings, however, of what happens next when Seynaeve orders Angelo to kill Bieke, the child prostitute. Understandably, the moral dilemma is easier for him to resolve when it is a question of killing in cold blood.

“I won’t do it,” Angelo tells Seynaeve. “She’s just a child.” When the latter says he’ll get someone else, Angelo tells him: “You don’t understand. No one will do it.”

For a moment, it looks as if the themes of memory and conscience are going to get a bit of an airing. Angelo is forgetting more and more things while popping pills to stave off the effects of his incipient memory loss, but he remembers that there are certain standards that even a hired killer won’t violate, a line that so long as he has any cognitive function at all, he will not cross.

Moreover, his assurance to Seynaeve that he won’t find anyone else to do the dirty work either suggests a shared standard, a sort of code of honor of the assassins’ guild that is as much a part of who Angelo is as any of the memories or personality traits that are beginning to deteriorate in him. Maybe more.

But Angelo is wrong. Seynaeve does find somebody willing to kill a child, and that suggests Angelo is a back number in more ways than one. As he strives desperately to hold onto his memory, to his self, the society around him seems to have relinquished its own moral identity without so much as a struggle.

To be sure, making the baron the chief bad guy is a bit old hat. When was the last time anyone can remember someone with a title in a sympathetic movie role? And he is also associated with that other favorite cinematic whipping boy, the Roman Catholic Church. Van Looy must have known that all he had to do was surround the baron with a priest and statues and candles to proclaim his villainy.

But even these lapses into movie shorthand have their purpose. It is to underscore the extent to which a country in which aristocrats and clergymen were once the most highly honored people is itself losing its collective memory.

It’s a good idea, even a great idea for a movie, but Van Looy doesn’t seem to know quite where to go with it. From this point on, the picture is a pretty routine thriller, as Angelo goes after the bad guys one by one while playing a rather too-familiar game of cat and mouse with the policeman, Eric Vincke (Koen De Bouw), who is trying to catch him before he can kill again.

Vincke, the jaded but sensitive cop, has also been done too many times before. And for an American audience, it may be a bit confusing to sort out the deadly bureaucratic rivalry between Vincke’s agency, a branch of the public prosecutor’s office, and the Gendarmerie, which is corrupted by the agents of the wicked baron.

By the end, the movie-ish qualities of the movie threaten to take over as the good cops are sent off by Angelo on a pointless treasure hunt for an incriminating audio cassette which is their only chance of thwarting the bad cops and nailing the baron. If he remembers enough to drop hints about where he has hidden the thing, why doesn’t he just tell them?

In short, the film is too long and unnecessarily complicated, and the most interesting thing it has to say happens halfway through. But Mr. Decleir’s Angelo almost makes it worth seeing. Anyway, you won’t be bored.