Plate I — Ascending and Descending

A closed circuit of stairs on a monastery roof. Every step climbs; the flight returns to its own first tread. Two files of figures pass each other forever, arriving nowhere.

Plate II — Regular Division of the Plane

A square lattice deforms into reptiles, then into birds, and never opens a gap. Mated edges guarantee the tiling: deform one edge and its opposite is bound to follow.

Plate III — Relativity

One building, three gravities. Each population stands upright in its own frame and walks on what the others call a wall. Choose a frame; the floor obeys you and betrays everyone else.

A gallery containing the print that contains the gallery. Enter it and you descend forever at a scale factor of one third, folded at the recursion period so no seam is ever visible.

Plate V — Day and Night

Polder fields rise into birds. The white flock is the black flock’s empty space, and the reverse. There is no background here — only the other bird. The press inverts from this plate.

Plate VI — Drawing Hands

The left panel is this plate’s own source, read at runtime. The right panel is what that source draws — which is this plate. Neither hand is the author.

Plate VII — Waterfall

Water falls, drives the wheel, and returns along an aqueduct to the top of the fall it just left. Three beams, three locally honest joints, one impossible closure.

Plate VIII — Circle Limit

A {6,4} tiling of the hyperbolic plane. In its own metric every figure is the same size; only our Euclidean eyes see them shrink. Travel as far as you like — the rim stays infinitely far away.

Plate IX — Impossible Cube

A real cube frame with three local lies. Orbit the engraved solid, then remove the impossible joint ordering to see the honest object beneath it.