Ritchie is a Glaswegian chancer with low hopes and no prospects. Disillusioned with city life, he goes undercover at a Highland conservation centre to make his fortune as an illegal pearl fisher with the help of his two hapless and accident prone mates, Danny and Fraser. Here he meets Beth, a pretty English conservationist passionate about saving endangered mussels from the clutches of pearl thieves in the Scottish Highlands. Falling for her instantly, Ritchie must beat off competition in the form of Highland Ranger Ethan, a smooth talking American Adonis convinced that Beth can't resist his charms forever. After the success of pearl fishing attracts the unwanted attentions of old school Glaswegian mobster Gavin and his work at the centre leads him to question his true motivations, Ritchie must risk life and limb to save the Highlands from ecological disaster and win Beth's heart.

Follows the turbulent relationship of Cole and Maya as they struggle to survive in a world where the human population has been decimated by an extra-terrestrial attack.