What is the significance of Jacob's vision of a ladder between heaven and earth? Why does it occur in a dream? This idea of ascending and descending on Jacob's ladder is a frequently used metaphor for the human spiritual journey. ‘Heavenly hosts’ shows where this metaphor has been much used in literature and film. It also asks: How many angels are there and are they heavenly or in fact alien? In the 1970s, alien enthusiast Eric von Däniken caused controversy by claiming that Abraham and Jacob did not meet angels but aliens.