You know a TV show must be doing something wrong when it's possible to sit and watch a family in torment over the disappearance of a child (possibly into a watery grave) and utter an audible sigh of apathy. Consider the lengthy, heart-wrenching scene at the beginning of Don't Look Now when Donald Sutherland's character drags his dead daughter out of a pond. In utilising a combination of unique visual and audio techniques, it builds tension and eventually provides an awful release. It's unbearable to watch. Then compare that to scenes in The Drowning which recreate, through the clichéd use of blurry slo-mo, the tragic realisation that four-year-old Tom has gone missing, most likely into the bottom of a lake. It's unbearable to watch but not for the same reasons.

There are some TV shows whose improbabilities and inconsistencies can be forgiven and overlooked if there are other enjoyable qualities to hold onto. The Drowning loses all potential goodwill by having characters conveniently bumping into one another or meeting in unlikely circumstances with a frequency that becomes almost laughable. Sadly, a couple of performances can charitably be described as below par, and the near constant use of a burbling, doom-laden score tells us that this is all very mysterious and frightening, rather than letting us feel that ourselves through the writing and acting.

The story: nine years after her son disappears, believed drowned but with a body never having been recovered, Jodie (Jill Halfpenny) spots Daniel (Cody Molko), a boy she insists carries himself like Tom (do toddlers and teenagers move the same way?), has similarly curly hair and an identical scar under his left eye. Within minutes, Jodie has managed to get a part-time music-teacher job at Daniel's school (the number of times the pair find themselves alone in a room or walking down an empty corridor together is ludicrous), and is showing up at Daniel's house much to the chagrin of widower Mark (Rupert Penry-Jones) who may or may not be his real father. To cut a long, laborious tale short, the true story behind Daniel's life and Tom's disappearance may be enough to keep you watching until Thursday, but the finale is unlikely to leave you feeling it was worth the agony.

Five, Monday 1–Thursday 4 February, 9pm. Watch on My5.