"All right." Libby looks thoughtful for a moment, and then a dark purple pentagon flickers briefly into her hand, and in the same moment that it vanishes, an... object... appears on the table. It's a black rectangle with rounded corners, about the size of a pocket calculator, but under the display at the top (which currently reads 0) there are only five buttons, each in the shape of a coin, from three to seven.

She expects that its use is probably self-explanatory, but if Ehail seems confused she can explain.