You climb ahead of Rolo, keeping one hand on the rail. Halfway up, he stops. His orange boot is wobbling on a loose step.
"Nobody move dramatically," he says.
Tessa braces the step with a fallen wooden wedge. Rolo shifts his weight, and the stair holds.
Beside the wedge, a repair drawing shows two poles crossed beneath a broken walkway. You point it out.
"A triangle brace," Tessa says. "Strong shape. Good spot."
Nib copies the drawing onto the back of his toast flag. Together, you climb past the repaired step and carry the idea up to the roof.