Prologue.- Purple haze: introducing our guide.- The early universe: the source of chemistry - and of our guide.- Shooting the rapids: the life, and death, of the earliest starlight.- Interlude - how our guide is hooked, lost and caught again.- Heading downstream and cooking by starlight.- Fishing for molecules.- Branching out: in the land of the giants and dwarves.- Interlude - trawling for our cosmic guide.- In the delta: exoplanets - worlds, but...