In the peaty depths of Germany’s Black Forest, nineteenth-century English gentleman Henry Brandling commissions a giant clockwork automaton so wondrous, so eerily lifelike, that he believes the very sight of it will restore his beloved young son to health and spirits. Nearly two centuries later, it lies in pieces in a small London museum where conservator Catherine Gehrig, reeling after the sudden death of her colleague and secret married lover, is given the job of re-building it.

Reluctantly, furiously – she would rather drink and cry herself to oblivion – Catherine digs in. She finds delicate steel rings and chains and glass rods, the makings of a beautiful mechanical bird. She also finds Brandling’s diary, in which she recognises a soul as lost and grief-maddened as her own.

Many tears fall in Peter Carey’s latest novel, streaming from the eyes of this couple who never meet but become companions of a kind: he desperate to avoid a devastating loss, she struggling to survive one. We meet her in shock, bouncing between trance and fury as she travels through a strangely stormy London to delete her lover’s thousand emails, one by one. The last, unopened before his death: “I kiss your toes.” Henry is a man looking for a miracle – and does not a machine that mimics life fit the bill? Brilliant enough to distract not just a sick child, but death itself?

It is a mechanical duck he orders, designed by a Frenchman, though he must travel to Germany (as ever, Carey does not stint with a rollicking traveller’s tale) to find his master clockmakers. But they are strange and secretive men, not easily commanded, and the mechanical marvel Catherine is persuaded to reassemble at the museum is a very different bird, with a mystery at its core. You cannot see what you can see is written in Latin on its silver beak.

The diaries, too – secreted in her flat with the vodka – start to slip focus: from the certainties of science and clocks to the awe-filled wonders of the universe, the unacceptability of truth, the persistence of human error. As Henry slips away from reality, Catherine returns to it, the last woman in London to notice the headlines about the Mexico oil spill, the hot wind blowing rubbish through the streets.

A bigger story, then. They’re calling it Carey’s global warming novel but it would spoil the fun – and subtlety – to reveal the secret of the bird, which may carry the seed of mankind’s destruction. Science does what it must; humans comprehend what they can. Carey makes this clear but leaves the reader to ponder the consequences while savouring a frisky, imaginative account of two companion souls grappling with love, grief and the possibility of magic.