The quest for discovery through looking is the driving force of Bridget Riley's work, as she has written: "More than anything else I want my paintings to exist on their own terms. That is to say they must stealthily engage and disarm you. There the paintings hang, deceptively simple- telling no tales as it were-resisting, in a well-behaved way, all attempts to be questioned, probed or stared at and then, for those with open eyes, serenely disclosing some intimations of the splendours to which pure sight alone has the key." This publication unfolds along the lines of Riley's 2018 exhibition at David Zwirner, London. Beginning with an exploration of black-and-white equilateral triangles, Riley leads the viewer into an awareness of the ways in which a surface-wall or canvas-can affect a seemingly simple form: the triangle. While she demonstrates these subtle changes, Riley manipulates this form by bending its sides. At first sight the viewer may experience this as a breaking apart, but as one continues to look, serpentine movements appear, or large shadowy triangles, which advance and recede. These paintings constantly reinvent themselves through looking. Riley is revisiting and developing works which she initiated over fifty years ago, as is shown here by the inclusion of Black to White Discs (1962-1965) in the exhibition. This diamond formation of discs, which graduates in tone from white to black and back again, offers a lead-in to her new body of work. In Cosmos and the Measure for Measure series, Riley recalls a group of subtly shaded colors used this time in discs. While the compositions remain fundamentally the same, the play of colors changes every time. The exhibition ends with a surprisingly spacious wall painting that offers the viewer many delights, not least among them a dance of fugitive white lights. Here, Riley disarms the viewer, encouraging us once again in an adventure of discovery. In his essay, Richard Shiff explores Riley's ability to give new life to basic forms as she invites the audience, any audience, to help participate in the painting.