Photon solar energy group is aiming to build a solar farm in Danebury. Blissfully unaware of the plan Andy and Lance are still looking for buried treasure - construction worker Andy, with Becky and their baby living with disapproving mother-in-law Veronica whilst Lance is sharing his flat with his messy, noisy teen-aged daughter Kate. The group is shocked to read of Photon's intention in the local paper - but then Andy makes a potentially interesting discovery.

Despite interruptions from curious ramblers Lance and Andy are finding more and more Roman coins. However Lance's sea-sickness leads him to see hypnotherapist Dr Hoffman so he can stay on girlfriend Toni's houseboat - though its success is questionable. Meanwhile rival detectorists Art and Paul have made their own arrangement with Photon, which Lance needs to challenge.

After Lance and Andy have raced Art and Paul to what they believe is a Roman burial site Andy quits his job when the boss destroys a Roman mosaic at the site. Unfortunately he fails to tell Becky when they go flat-hunting. Lance is jubilant at finding a gold coin but he is not happy when a magpie flies off with it - and Maggie, on her own again, decides to return to him when he is hoping to have Toni stay at his flat.

Lance and Andy pitch a tent to guard the field but with Andy, having quit site work for killing weeds by the road-side, Lance keeps a lone vigil to catch the magpies stealing coins - and fails. Nor is Toni happy that he lied about Maggie staying with him and it is down to Kate to get rid of the unwanted visitor. Andy also finds an unusually sympathetic ear in Veronica.

As Lance and Andy determine to save an oak tree in their field Kate puts in a good word for her father with Toni, with positive results. Andy is also pleased to discover a run-down cottage he feels he and Becky can afford to buy at auction and, in his efforts to save the tree, inadvertently comes upon the answer to his problems, despite the efforts of Art and Paul with the Bat Action Trust .

As Kate moves onto Toni's houseboat allowing Toni to move in with her father, Lance and Andy call a truce with Art and Paul, allowing them to excavate the potentially valuable field. Thanks to Veronica, Andy and Becky can buy the cottage but the pursuit of treasure still proves to be elusive to the group.

With the scout hall suffering from lack of funding, Andy and Lance have the perfect way to raise funds with their new dig. But why does Lance want to keep it a secret from everybody?