Recent scholarship suggests that the data available about lost plays from Shakespeare’s lifetime has never been greater, better assembled or more accessible. What can be done with all this new knowledge? In this Introduction, I examine the numerous and varied reasons why plays become lost – fire, vandalism, censorship (including self-censorship), legal notoriety, the logistics of publishing or preserving a play – and dispel the myth that survival is associated with quality. Indeed, the example of Shakespeare’s ‘Love’s Labour’s Won’, examined here as a case study, contradicts every generalisation about why plays become lost. Accordingly, I argue that a revaluation of the role played by lost drama in the repertories of early modern playing companies is urgently needed. I approach the question of coping with loss by thinking in pragmatic terms about how scholars can and should incorporate discussion of lost plays into their work on substantially extant texts. I introduce the metaphor of ‘Rubin’s Vase’, a visually experienced figure derived from the work of Danish psychologist Edgar Rubin, as a means of understanding the relationship between lost and extant plays. Lost plays, as a kind of ground or negative space, bring our picture of early modern drama into sharper relief.