In reading order
Passengers of the Underworld
Sabine Blackwood
The Cursed Carnival
Sabine Blackwood
The Mask of Memories
Sabine Blackwood
The Ghostly Guardian
Sabine Blackwood
The Siren and the Sleepwalkers
Sabine Blackwood
The Forgotten Key
Sabine Blackwood
The Ghostlight Theater
Sabine Blackwood
Curse of the Lost Coin
Sabine Blackwood