Claire (name can be changed) and her team of contractors arrived at the island.

The island was the private property of the wealthy Ainsworth family
whose empty mansion -- popularly known as Coffinhenge -- was damaged by nesting birds.
Claire and her team were hired to clear away the birds, which they did,
but the boat that was supposed to take them back to the mainland didn't come.

As the weather turned sour, they decided to spend the night in Coffinhenge.

That was the start of strange and tragic events......

[From DLsite English]