The Phantom Child by A.J. Wills

Is her child really missing? Or did he never exist at all?

With cracks beginning to show in her marriage, Karina thinks a short break to a luxury villa in Turkey with her husband, Ronan, and their four-year-old son, Jacob, is just what the family needs.
It’ll be a chance to relax, enjoy some good food, and more importantly to reconnect with the people she loves the most.
But on their first morning, Karina is startled to discover she’s slept in late and not been woken by Jacob.
He’s an early riser who always comes into their bed pestering them to make him breakfast.
So where is he? A needle of fear spikes through Karina’s veins.
She rushes to his room, but his bed is empty and he’s nowhere to be found in the villa.
But when she wakes Ronan, frantic with worry, and tells him their son is missing, he stares at her blankly.
He says he has no idea what she’s talking about and that they don’t have any children.
He’s certainly never heard of a boy called Jacob…