Easy Summary: The Girl in Cabin Zero

Introduction: The Ticket That Should Not Exist
Sixteen-year-old Adrian Mercer is traveling with his mother and younger brother on a ferry called the Northern Star. The ferry is sailing to Port Astor. At first, the trip seemed peaceful and safe. Families enjoy the sea view, children play, and music comes from the café.
Adrian expects a quiet holiday, but everything changes when he finds a strange passenger ticket under a bench near the Grand Staircase.
The ticket belongs to a girl named Elena Vale.
Her cabin number is listed as Cabin 0.
Adrian is confused because he has already looked at the ship map. All the cabins begin with number one. There is no Cabin Zero anywhere on the map.
Then Adrian turns the ticket over.
A message is written on the back:
If they find this, they will know I survived.
Now Adrian knows this is not an ordinary lost ticket.
A crew member named Martin Calder sees the ticket. Instead of being surprised, Calder looks frightened. He tells Adrian there is no Cabin Zero and orders him to throw the ticket into the sea.
This makes Adrian even more curious.
Why is Calder afraid?
Who is Elena Vale?
And what did she survive?
As night falls, the ferry begins to feel different. The bright halls become dark and quiet. Crew-only doors and hidden stairways seem more mysterious.
While Adrian's family sleeps in Cabin 318, he decides to search for Cabin Zero.
He does not know that his search will lead him into secret tunnels, hidden rooms, stolen treasures, and a dangerous murder mystery. He will also discover that people aboard the ferry are trying to hide the truth.
Adrian knows only one thing:
Someone does not want Cabin Zero to be found.
And he is determined to discover why.

THE END