Knock Three Times!
Author: first_name: Marion St. John
last_name: Webb
Language: English
Year: 1919

“Jack and Molly were twins, and this was their ninth birthday. Such a happy, exciting day it had been; it felt like a birthday all day long, so you can guess how jolly it was, and how special it made Jack and Molly feel. Little did they guess what a weird and mysterious end to the day was now approaching!....
“Had Aunt Phœbe known when she bought ‘this useful little thing’ what it Really Was—could she have foreseen any of the mysterious happenings that were to follow the arrival of her birthday