The term Aliyah Bet refers to illegal Jewish immigration to Palestine in the period of the British Mandate for Palestine; it constituted one of the most effective methods of struggle of the Zionist movement for the sovereign state of Israel. Its history is marked, on the one hand, by clandestine activities and spectacular operations, and on the other, by dramatic events (catastrophes of sea liners carrying immigrants, deportations of refugees). The book discusses events without which one cannot understand the contemporary Israel.