The day Adam leaves her, Gemma takes her heightened emotions, her now-ex-mother-in-law's hot pink wellies, and a pair of yellow Marigold gloves down to the River Thames. She thinks finding historical objects in the hotchpotch of pebbles, rocks and mud is the only way to distract from her heartbreak. Until she meets an eclectic group of people who love to do the same thing. As the mudlarkers begin to open up to each other, Gemma realises that they are not just bonding over the wonders of the past, because what's in the present might be more important. And perhaps friendship is not the only treasure to be found on the banks of the river.