Sarah Robinson and Rob Grindon bought it two years ago, when the estate agent described it as Georgian. Its name comes from a large mulberry tree in the garden, which legend says was planted by James I in 1603.
But ever since then, Sarah has experienced some fairly traumatic events. She says a ghost has assaulted her by uncorking a bottle of wine and pouring it over her. And a friend who had been staying the night screamed as he thought he saw an apparition walking through a wall. This instantly raised a question: "Had there been a door there once?"
As the house was still being renovated, the detectives were able to dig through the plasterwork to reveal a bricked-up space where once there had been a door - and this is where the guest saw the ghost disappear. In a suitably spooky vein, some plaster that Sarah had uncovered had a tuft of hair attached to it. Too fine for horse hair; perhaps it was dog hair, or even human hair, one of the detectives mused.
The cottage has other interesting anomalies. The first is a grandly elaborate staircase - its proportions are out-of-kilter with the intimate scale of the building. Judith Miller is soon able to pin down this discrepancy: the staircase was inserted between 1900 and 1905. The newel - the end- post of the stair rail - has elements of Jacobean and Edwardian design intermingled, with a fake wood surface painted on to it.
But further mysteries beckon: which is the older part of the house, the front or the back? It seems that the front is, but after a trawl through the maps it is clear the front was in fact the later addition, pushing out into the old high street.
Sarah has also noticed there are often unpleasant smells in the sitting- room. So dowsing rods were brought into action. Mac Dowdy uses them regularly to test for water, and it seems a stream runs under the room as the rods twitch when he walks across the floor. He plots the course of the underground source into the back garden.
But in what proves the most satisfying revelation, the team is able to fix the date of the dwelling to 1474. And there is more: a series of land strips that run right along the coast, and account for the narrow shape of the garden extending back from the house, almost certainly indicate the presence of a settlement dating back to the Bronze Age.
It is a distinction with which the owners are delighted, and confirms Sarah's original conviction that the the house was much older than Georgian, which was suggested to her when she bought it.
'The House Detectives', Tuesday 8pm, BBC2.Reuse content