The Sign of Four

This is an Intermediate Level story in a series of ELT readers comprising a wide range of titles - some original and some simplified - from modern and classic novels, and designed to appeal to all age-groups, tastes and cultures. The books are divided into five levels: Starter Level, with about 300 basic words; Beginner Level (600 basic words); Elementary Level (1100); Intermediate Level (1600); and Upper Level (2200). Some of the titles are also available on cassette.