Complex sentence: Her novel "The Circular Staircase" (1908), adapted as "The Bat" (1926), tells the story of guests in a remote mansion menaced by a killer in a grotesque bat mask.
Split into simpler sentences: Her novel "The Circular Staircase" (1908) was adapted as "The Bat" (1926). The story is that of guests in a remote mansion being menaced by a killer in a grotesque bat mask.