For a film that begins with the remark "this is the truth, sorry", The Fault in Our Stars could up its honesty quotient. Slickly made and very nicely acted within the confines allowed by the script, Josh Boone's adaptation of John Green's young-adult blockbuster novel nonetheless can't help but sell candour (not to mention plausibility) down a tear-laden river in its tale of young love cut short by cancer.

I was more or less going along with a narrative that sells its lack of sentimentality like a badge of honour - until a scene set at the Anne Frank House in Amsterdam of such startling insensitivity and phoniness that all the movie's faults suddenly come crashing down around it.

To backtrack, this is the tale of Hazel Grace Lancaster (Shailene Woodley, making her bid for the big time), an indrawn 16-year-old with a conspicuous lack of friends who was diagnosed age 13 with cancer, since which time she wears plastic tubing to help her breathe and carries around a portable oxygen tank as a visual reminder of the baggage - both physiological and psychic - that her illness has brought with it. Wry, sardonic, and determined not to milk her ailment for easy bathos, Hazel finds her self-containment thrown amorously off-guard by the arrival in her life of Augustus Waters (Ansel Elgort), a dashing, witty 18-year-old who has lost part of one leg to cancer. Completing the adolescent triptych is Gus's great friend Isaac (the winning Nat Wolff, an alumnus of Boone's 2013 film Stuck in Love), who is going blind and spends most of the film sightless, his eyes hidden behind dark glasses.

One instead waits in vain for any of the characters to be resentful or dangerously angry or even to indulge the self-pity that is theirs by right, and one includes in this parents who on this evidence constitute a supremely self-sacrificing lot, the excellent Laura Dern and Sam Trammell as Hazel's mum and dad chief among them. (The two are pictured above left.) A final meltdown from Gus notwithstanding, our central pair ultimately come across as ever-attractive, always-engaging poster children for forbearance. Where are the abrasions - the rough-and-tumble of the soul as well as the distress to the body - that arrive all too fully with illness? On this evidence, they remain tucked away behind preternatural poise until such time as there is a cue for tears. This movie can parade its "truth" as much as it likes, but I for one don't buy it.