Once in every line
Each row and each column holds every shade exactly once. Set the same glass twice in a line and the lead cracks red.
Nave · Light 2
0 of 8 panels lit
Pick a glass from the rack, then set it in a pane.
The glazier's three laws
A window is a square of panes, as many shades of glass as it is wide. Thick lead binds the panes into panels, and three laws decide every one of them.
The panel's number
A panel marked 7+ must add to seven; 2÷ means one glass is twice the other. Two-pane panels may subtract or divide, larger ones add or multiply.
Light, not luck
When a panel's glass is right it lights in amber, ruby, sky or moonlight. Every window has one glazing, and reasoning alone gets you there.
Four kinds of window
Forty-seven windows wait along the ground plan, from the Narthex at the west door to the Lady Chapel behind the apse. After the Crossing, the two transepts may be glazed in either order.
Lancet
Every panel shows its number and its sign. The nave is glazed this way, 3×3 up to 7×7.
Grisaille
The signs are painted over in grey. Work out whether a panel adds, subtracts, multiplies or divides, and its true colour shows.
Saltire
Two gold fillets cross corner to corner, and both diagonals must hold every shade as well.
Lady Light
The last window joins grey paint and gold fillets in one 7×7 pane of glass and reasoning.
Evenings and candles
At Vespers one window waits each evening, the same for every glazier that night. Glaze it before the day is out; an evening that passes simply passes, with nothing lost.
Candle Rush lays small windows on the bench one after another while a candle burns down. Each restored window adds wax, clean ones lengthen a chain up to five, and a crack breaks the chain.
Restored windows earn ambers for the Tracery, a shop that grows like window stonework: sun shafts, cartoon sheets and lenses to help at the table, new glass that changes the colour of every lit panel, gilded or verdigris lead. Crown-glass bullseyes fill a shelf as the cathedral comes back to light, and the fabric rolls keep the accounts of every pane you set.