Tell-tale Seaweed

Spooky story
Not mine

Two sisters were motoring through Cape Cod late one stormy night in the early 1900's when their car broke down in an unpopulated area. Seeing an old, neglected house nearby, they went to the door and tugged on the bell-pull. When no one answered, they looked through a nearby window whose shutter was banging in the bitter wind. The window was broken. Through the window, they could see a library. The dust lay heavy over everything.
The women decided to take shelter for the night and find someone to tow the car the next day. They brought blankets in from the car, their feet leaving tracks in the thick dust of the floor as they settled in for the night.
Sometime later, they were both suddenly awakened. A bedraggled sailor, dripping wet, was standing next to the fireplace as if he were looking to dry himself before a non-existent fire. The sailor was glowing in the dark. The braver of the sisters finally called out a strangled: "Who's there?"
The sailor muttered something they could not make out and disappeared. Deciding it was a dream, the sisters lay back down to sleep. But the next morning, they found a patch of wet salt water by the fireplace, and a piece of seaweed. And there were no footprints in the dust by the fireplace apart from their own.
The sisters hurried out to their car. Soon, they were given a tow to the nearest village by a passing motorist. There they asked about the abandoned house. They were told the house had been empty for years. The people who owned it had a son who was driven from home by his father and had drowned at sea. The family had moved away because they claimed strange things kept happening at night.
A few months later, one of the sisters told her tale at a dinner party. A museum curator seated near her volunteered to test the seaweed for her. The curator sent her a message several days later. The message simply said that the seaweed she had found in the abandoned house was a rare type of seaweed only found on dead bodies.