“Is it too weird?” asks Clare (McAdams) as she watches her five-old-daughter Alba literally talking to herself on the back patio of her family home.

Because young Alba is actually chatting away with the 11-year-old version of herself, the same child but one that – thanks to an inherited genetic anomaly – can slip through time.

To streamline the weighty conceit of Audrey Niffenegger’s source novel, director Robert Schwentke has disposed of a host of peripheral characters to focus on Henry (Bana) and Clare.

He’s a “time traveller”, a sad soul – cursed or blessed - with the ability to involuntarily disappear and wind up in the past – or future – but can always find his way back.

Since Clare was a little girl, Henry – risking an entry on the Paedophile Register - has been popping up unclothed Terminator-style on her father’s country estate to have a little chat…and gradually fall in love.

Now that Clare’s an adult woman they desperately fight to maintain an ordinary life together…but he’s the worst case imaginary friend and ultimate absentee father.

Keeping the sci-fi slant for comedy value (Henry’s Houdini routine), Schwentke movingly focuses on the dramatic stresses Henry’s disappearing act place on their relationship, one that is complicated further still with the arrival of Alba.

It’s finely acted and there’s enough wryly amusing vignettes – Henry’s consultations with a disbelieving shrink (Stephen Tobolowsky) and his engineering of a $5m lottery win – to offset the darker undercurrents.

Of course a suspension of disbelief is essential, but – if you can sideline the illogical nature of the plot – what emerges is an intimate and moving love story.

Make time for it.

Tim Evans